Hi Dean,

it is one of the most problematic issues in info path. You can make youre
.NET assembly (dll) and reference it in InfoPath. The dll must be signed and
I think the form must be FullyTrusted. But the problem begins when you want
to make change in the dll, and implement the change in all of the forms in
which you used the dll. In order that the InfoPath template is an XSN file,
the file is published on some location, holding the dll in self. So it is not
referenced from outer location. The template holds the dll in the xsn (thats
CAB file).

I hope this will solve some of youre problems

Darko