Change the Temporary Variables set in TC project via Visual Studio Test in TFS

I just want to know if its possible to change the "Temporary Variables" you set in a project, in TC, via Visual Studio Test task or other tasks, in TFS?

For example say that I have a couple of build definitions created in TFS, and every definition point to a different server.

And in my TC tests I have pointed out in the "Temporary Variables" which URLs it should point to.

So when it come to the builds in TFS I want to replace the URLs set in "Temporary Variables", with new URLs, specific for that specific build.

So now I wonder if this task is even possible? Replacing variables in TC tests, with Visual Studio Test task or other tasks available for TFS.