An otherwise prolific programmer who runs KillerSite.com bemoans the difficulty of SOAP in VBA (that's Visual Basic for Applications, ie. Excel Macro language)
I'm having quite a time working with MSSoapLib... I searched all over Google and Google Groups but have found nothing helpful...He documents more troubles here. I don't know what service he's trying to use, but attempting to use the AdWordsAPI from VBA is a huge pain in the ass, so far.
The best place I've found for help are the xml and Excel VBA forums over at p2p.wrox.com. However, much of the Microsoft world is moving away from VBA towards Visual Basic .NET. The big advantage of VBA is you don't need a several thousand dollar investment in Visual Studio .NET to write a program that sends 400 bytes of xml over http. The disadvantage is that you can't get anything to work, and it's hard to debug... at least for me.