We don't help with "hacking" the mirc.exe file. For Windows XP (I can't remember older versions but it's probably similar) you can change the mIRC
shortcut icon by right clicking it, going to Properties and clicking on the 'Change Icon' button.
MDX.dll also allows you to change the little icon in the top left hand corner of your own dialogs - but not the main mIRC window. There's no need to completely hide what program you're using.
Regards,