TFS and Checkin Policies / associating Work items

[gtschech]

I'd like to use MS Team Foundation Server (2005) as the Source Control repository for our Sparx (6.5) project.

The TFS Source Control, however, requires users to assign every checkin with a workitem to assure that no work is done without a requirement to do so.

Now when I try to checkin from Sparx, I only get an alert saying that I violated the Checkin rule to speicify a work item, but I don't see any dialog where I could select one.

How can I bring up the Checkin dialog (as seen in Visual Studio) from the Sparx checkin procedure?