>Does COM interface allow you to cross 32/64-bit boundary? For example, would VFP (a 32-bit app) be able to use COM to interface to 64-bit application? Say for example I'm using COM to MS-Excel to implement a "wide" report (spans multiple pages horizontally, Excel provides convenient way to tile output), will it eventually break when used on 64-bit OS with 64-bit edition of MS-Office?

I don't expect a 64-bit version of MS Office to be released for many years.