Unless VSIP SDK (search Google) allows that, add-ins can not automate
"unmodeled projects", such as Setup projects.

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Carlos J. Quintero
MZ-Tools 4.0: Productivity add-ins for Visual Studio .NET
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>I have a custom project template that creates a solution containing a
>webform project as well as a setup project. I would like to automate some
>of the tasks associated with the setup project, ie. adding the primary
>output and content files from the webform project. However this .vdproj
>project type does not seem to be accessible thru automation. Any ideas?