Help with Visual C++ program

Hi,

I am trying to edit/"re-write" an existing program that is freeware related to my hobby which is ametuer radio. I want to customize by taking it apart and looking at how it has been programmed, then edit or change that to my needs so that it performs specific functions better suited to what I am using it for. Any help, suggestions, or even the terminology for this would be greatly appreiciated. I have already found out that the program was written is Microsoft Visual C++ 6.0 ......is there any program that I could find that would let me "look" at how the program works?
Thanks for your time
Steve

If you don't have the source, forget it. The are some programs around, (decompilers), which will convert an executable back to some assembler, but it rarely is productive to try to go any further.