calling script from within script.... (VB)

I've got the scenario where I'll be creating a VSA engine and calling into a
function in scripted vb.

If I want this script to reference object, I need to ensure they're added to
the engine using the IVsaReferenceItem object, then use the "imports
<object>" in the script.

But what if I want to call another script file within my current script?
Is there anyway to do a "#include <filename>" type commna to incorporate
another script file into the current script?

Thanks.
Dan.
ps. VSA is not really that popular... there's a hand ful of articles on the
net about it, and MSDN only really contains the stuff about the actual
framework objects. Is it a technology that's going to advance and become the
scripting standard, or is it going to be canned?