Wow...haven't seen VB4 in quite some time! First off, I should note that I don't believe that any of your code is using NI Measurement Studio or other NI controls for Visual Basic. That said, I will still try to offer a little advice.
I don't know of an easy way to port your 16-bit VB4 code to Win32. In theory, if you load your project into VB5 or VB6, most of the code should actually work ok. Not much changed in the language syntax between those version. What won't work, however, are most of your forms or other UI pieces. With VB5, Microsoft moved away from using the old VBX controls in favor of embedding ActiveX controls (OCX) onto the forms.
I'm not familiar with what the MHGFRM control even does. There's not a lot of info on the web about it. I did find an old product readme from a sybase product from back in 1996 that mentions it but as best as I can tell, they didn't own the component but rather also used it for some necessary parts of their UI.
Either way, even if you had the control, my guess is that there's not a perfect port of it to an ActiveX control. I don't see any way around rewriting that portion of the functionality.
With regards to your debugging question, the .vbp file won't open in VS 2005. In VB5, Microsoft added the capability for VB to compile in debug symbols which made it possible to attach the Visual Studio debugger to a VB app and walk through the code but I don't think that support existing in VB4.
Good luck!
Jason
