Activex, COM, OLE server, oh my...

[rmccraw]

Can anyone suggest an underlying technology that would let me share code between Excel and some non-Office platform that display forms, plus links to a concise description of that approach? Whatever it is, it must work with earlier versions of Office.

Background: I have an application whose functionality is split between extensive VBA code (Excel add-in) and equally extensive Visual FoxPro code. There is lots of overlap between the two, and I'm spending more and more time writing code in VBA, then coding the same functionality in FoxPro. So, I want to be able to write code that can be shared between the two. The Excel part is the most critical and must remain. However, I am perfectly willing to completely replace the FoxPro component with something like Windows Forms (or pretty much anything else).

By now, I've spent many days researching my VS options. My first thought was Activex, but Office can't seem to handle controls that contain such form elements as treeview. Once I moved beyond that point, I quickly became bewildered by the options. I played with some, but none seemed to quite do all of what I need.

Oh, and in case it isn't obvious already, I'm new to VS.NET.

Many thanks.
--
Rick
Developer/teacher