You're probably in for a bit of work :-)

It's possible to build just an editor for .asm files using the VSIP SDK. If
you want to do this with VB .NET, you'll also need to download the VSIP
Extras package to get the necessary interop DLL's. There's very little in
the way of VSIP samples using VB .Net. Currently, most of the bigger
samples are written with C++, and there are a few VB and C$ sample VSIP
packages that come with the VSIP Extras stuff.

For an editor to support syntax coloring, and intellisense, you would need
to build a language service package. Also something that requires the VSIP
SDK.

And to really complete the integration, you'd probably want to build a
project system for assembler projects as well, and then build your wizards
and templates.

Such a project is not a trivial undertaking, but if you download the VSIP
SDK, (and VSIP Extras), you'll want to pay particular attention to both the
MyC and Figs VSIP samples. These two samples are the ones that implement
most of the mentioned features above. Though both are written in C++.

Sincerely,
Ed Dore [MSFT]

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