Hi Chris,
Many thanks for getting back to me.
Yes, we did change everything to use the MS-Office Interop classes.
I looked at a few VB and C# forums to try work out how to replicate things like "Marshal" or "GC (Garbage Collection)" in the Visual Cobol code but am a bit baffled at the moment. If it proves to be a few hoops to jump through then I'll look at going back to the COM support in the native code project.
John