Does the Windows version support COM/OLE?
Yes,
BBC BASIC for Windows is supplied with the
COMLIB library, and that library requires only a trivial modification to run in the Windows edition of
BBC BASIC for SDL 2.0 as well.
There's an example program which uses that library to access the
TTS (Text To Speech) functionality in Windows, which has a COM interface.
I also know of one user who uses it to automate Microsoft Office products like
Excel, using their ActiveX interface.