This code searches all loaded *.mrc files for the search string.
If the search string is found, each occurrence of the search string,
along with the file name and line number, is displayed in a custom window.

Furthermore, double-clicking a line in the custom window will automatically
open the corresponding script file and place the cursor at the beginning of
the line containing the search term.

I also use similar code to list every occurrence of an alias, which I find
particularly useful in debugging.

I hope it works OK for others.

; Usage : /searchfor sometext
; and double-click an item in the resulting window
alias searchfor {
  window -l -t30 @search | clear @search
  %scripts = $script(0)
  %searchTerm = $$1-
  while %scripts {
    filter -fkn $script(%scripts) extract *
    dec %scripts
  }
}

on *:close:@search: {
  unset %scripts
  unset %searchterm
}

alias extract {
  if %searchterm isin $1- {
    aline @search  4 $+ $script(%scripts)12 $chr(9) $+ 12 $+ $1-
  }
}
menu @search {
  dclick: {
    var %selected = $line(@search,$1,1)
    tokenize 32 %selected
    var %scriptFile = $strip($1)
    var %scriptline = $strip($2)
    var %nopath = $nopath(%scriptfile)
    clipboard %nopath
    showmirc -s 
    sendkeys % $+ r $+ % $+ r $+ ^ $+ m $+ ^ $+ v $+ {enter}
    timer -m 1 500 /gotoLine %scriptLine
  }
}

alias -l gotoLine {
  clipboard $1
  sendkeys ^ $+ g $+ ^ $+ v $+ {enter}
}

alias -l sendkeys {
  var %object = sendkeys $+ $ticks
  .comopen %object WScript.Shell
  if ($com(%object)) { .comclose %object $com(%object,SendKeys,3,bstr,$1-) }
}