Save in mIRC folder as a .mrc...
In a channel the use is /big TEXT
Ex.
/big Hello -- Messages channel: HELLO (In big letters)
To refer to it, use $big(text)
Ex.
//say $big(Hello) -- Messages channel: HELLO (In big letters)
there is an ifabet this has bigtext which you can change the colours, its the first link off google, thats the only one i found the link for
its ini code, if you want to make it show up when you right click add this at the bottom:
n522=alias IFbigdia {
n523= if ( $dialog(IFBLTdia) ) { dialog -v IFBLTdia IFBLTdia }
n524= else { dialog -md IFBLTdia IFBLTdia }
n525=}
n526=menu Channel,Query {
n527= Colour bigtext:ifbigdia
n528=}