automate fax service from a service?

I'd like to write a program that use the MS Fax Service on Windows
XP / 2003 to submit faxes and processing incoming faxes. My question
is, does the "Fax Service Extended COM API" work when called from a
service? I know I could try it, and I suspect it would work on the
surface, but I'd like to know if it will really hold up under
extensive testing. So far the interface methods I need to call do not
require any window handles, however sometimes a window is displayed
(like the fax progress window).

Also, and maybe I need to post this part to the GDI group, does
Windows XP+ include an API for working with TIFF images (the format
that MS Fax Services uses)? I know about GDI+, and would use it, but
MSDN says it can't be used from a service. I also know about .NET,
but I don't want to require/support .NET yet, so (sorry) that just
isn't an option for me yet. I would like something from Microsoft
though, not libtiff (tifflib?) or other non-MS solutions. Mostly I
need to convert the TIFF files from MS Fax Services to BMP (1 per
page) (actually something else, but if I can get to BMP, then
everything else is easy).