
SubCL allows you to subclass windows while using breakpoints, Pause and Stop button in VB6 IDE. It's easy to use and safe (i hope). I combined Paul Caton's WinSubHook2">https://www.vbcoders.com/vb/scripts/ShowCode.asp?txtCodeId=51403&lngWId=1">WinSubHook2 and Karl E. Peterson's HookXP">https://vb.mvps.org/samples/HookXP/">HookXP (though it wasn't very easy to write ASM procedure:-)
To use this code in your project you need to include only 1 file - csubcl.cls.
More info in a screeshot and source code.