The basic method is something like this
objFolder.Items.Add("IPM.Note.Your Custom Form")
There is a pretty good resource at
www.outlookcode.com (and an example of this specific question is at
http://www.outlookcode.com/d/launchform.htm). The site also covers additional issues you need to consider, such as where and how to publish to form so it is visible to everyone, etc.
>Does anybody now how you can programmatically choose an outlook form prior to sending an email?