Add a download site to update project via command line

Presently, we are using the wybuild.cmd.exe to add a version to the update package. This is working well for us. Using this method we are also able to create a test and production updater. One for each environment by swapping out certain files from our update package. The test updater gets fileX and the production updater gets fileY. Works great.

Now we'd like to take this another step and specify which download site that the client.wyc file should have in it. When building the test updater, use download site A. When building the production updater, use download site B.

Is there a way to add a download site via the wybuild.cmd.exe?

We are familiar already with the existing command line switches on wyUpdate.exe (-server and -updatepath) We use that for testing as well. That's not what we are after in this question.

Is this possible?