mIRC WHOIS Information in @whois Window - when a user joins the channel, automatically the whois information will be sent into the @whois window.

The best thing is that all whoises will happen in the @whois window and won't get mixed on any of your chat/s within the channel or query. Simply paste on your remote and save. I am not sure if will work with other IRC clients, but you can give it a shot. I was using this back on JUN 1ST, 2016, and started using this again lately so I know it's still working. Just throwing it in here, in case someone wants to use it.

If you are an operator and only want to use it in a specific channel, just change line 15, after the # put the channel name.
Example: #channel
For multiple channels, type: #channel1,#channel2,#channel3 (so on and so forth, separate them with a comma).

*************************************************************************
**************** mIRC WHOIS Information in @whois Window ****************
******************************* by: zcnut *******************************
*************************************************************************

- Active On-Join Check in all joined channels
- Displays Nick, Fullname, Ident@IP, Network Info, Connect time & Idle
- Display the target's CLONE/s in the channel (current/real time)
- Displays if target is logged in as a regular Cservice User or IRCop
- Displays Joined & Common Channels, Client info and set away
*************************************************************************
  Paste on your mIRC remote and save.
*************************************************************************

ON !*:JOIN:#: { inc -u5 %check.floodpro 1 | whois $nick $nick }
if (%check.floodpro == 5) { /.disable #whoisonjoin | .timer 1 60 /.enable #whoisonjoin }

menu nicklist {
  — $1  —:whois $$1 $$1
}
raw 311:*:{
  haltdef
  window @whois
  echo @whois $timestamp 5•---------------• 14[Begin Whois Info:8 $2 $+ 14] 5•---------------•
  echo @whois $timestamp 14|---› 14Nick:1 $2
  echo @whois $timestamp 14|---› 14FullName:1 $6-
  echo @whois $timestamp 14|---› 14Ident@IP:1 $3 $+ 14 $+ @ $+ 01 $+ $4
  var %clone = $kanalclone($2)
  if (%clone == $null)   echo @whois $timestamp 14|---› 14Clones:1 (No Clone)
  else   echo @whois $timestamp 14|---› 14Clone:1 ( $+ $numtok(%clone,44) $+ ) user 04/01 %clone
  haltdef
}
raw 313:*: {
  haltdef
  window @whois
  echo @whois $timestamp 14|---› 14Network Info:1 $3 $4 $5 $6 $7 $8 $9
}
raw 314:*:{
  haltdef
  window @whois
  echo @whois $timestamp 14|---› 9•---------------•
  echo @whois $timestamp 14|---› 14Nick:7 $2
  echo @whois $timestamp 14|---› 14FullName:7 $6-
  echo @whois $timestamp 14|---› 14Ident@Ip:7 $3 $+ 14 $+ @ $+ 01 $+ $4
  var %clone = $kanalclone($2)
  if (%clone == $null)   echo @whois $timestamp 14|---› 14Clones:5 (No Clone)
  else   echo @whois $timestamp 14|---› 14Clone:1 ( $+ $numtok(%clone,44) $+ ) user 04/01 %clone
  haltdef
}
raw 317:*:{
  haltdef
  window @whois
  echo @whois $timestamp 14|---› 14Connect Time:1 $asctime($4) 04/1 $duration($calc($ctime - $4))
  echo @whois $timestamp 14|---› 14Idle:1  $duration($3)

}
raw 319:*:{
  haltdef
  window @whois
  echo @whois $timestamp 14|---› 14Joined Channels:11 $3-
  echo @whois $timestamp 14|---› 14Common Channels:10 $ortak_k($2) 04/01 Total:04 $comchan($2,0) 01Chan(s)

}
raw 338:*:{
  haltdef
  window @whois
  echo @whois $timestamp 14|---› 14Real Ip:01 $4 $5 $6

}
raw 320:*:{
  haltdef
  window @whois
  echo @whois $timestamp 14|---› 14Swhois:1 $2-

}
raw 330:*: echo @whois $timestamp 14|---› 14CService Login:1 $2  $4 $5 $6 $7 $3 | halt
raw 378:*:{
  haltdef
  window @whois
  echo @whois $timestamp 14|---› 14Real Ip:01 $3 $4 $5 $6 $7

}
raw 379:*:{
  haltdef
  window @whois
  echo @whois $timestamp 14|---› 14Modes:01 $6
}
raw 671:*:{
  haltdef
  window @whois
  echo @whois $timestamp 14|---› 14Connection:1 $3-
}
raw 276:*:{
  haltdef
  window @whois
  echo @whois $timestamp 14|---› 14Client :1 $3 $4 $5 $6 $7
}
raw 327:* {
  window @whois
  echo @whois $timestamp 14|---› 14Client Info:1 Java User
  halt
}
raw 301:*: {
  haltdef
  window @whois
  echo @whois $timestamp 14|---› 14Away:1 ( $+ $3- $+ ) 
}
raw 310:*: {
  haltdef
  window @whois
  echo @whois $timestamp 14|---› 14Ircop:1 $3 $4 $5 $6  

}
raw 335:*: { 
  echo @whois $timestamp 14|---›  14Bot:1 Yes (+B).  
  halt
}
alias kanalclone {
  if ($ial($address($1,2),0) == 1) return
  var %nickler = 0 | var %clone = $1
  while (%nickler < $ial($address($1,2),0)) { inc %nickler | var %clone = $addtok(%clone,$ial($address($1,2),%nickler).nick, 44) }
  return %clone

}
raw 318:*:{
  haltdef
  window @whois
  .timer -h 1 200 echo @whois $timestamp 5•---------------• 14[End of Whois Info:8 $2 $+ 14] 5•---------------•
}

alias ortak_k {
  if ($server == $null) {   echo @whois $timestamp 14|---› 14No such server. }
  elseif ($chan($me) == 0) {   echo @whois $timestamp 14|---› 14No such channel. }
  elseif (!$1) {   echo @whois $timestamp 14|---› 14No such nick. }
  elseif ($comchan($1,0) == 0) {   echo @whois $timestamp 14|---› 14No such nick/channel. }
  else {
    var %oid 1
    set %orka $comchan($1,0)
    unset %knms
    while (%oid <= %orka) {
      set %knms $comchan($1,%oid) $+ $chr(32) $+ %knms
      inc %oid
    }
    return %knms
  }
}

I can't customize this for whatever or how else you want this to work for your purpose. IT IS WHAT IT IS.
Good luck and thank you!