Keep GUI active when RDP is minimized or closed

I'm currently working on a gui testing application (mouse actions and such things).
When i run it on a remote machine, the GUI will only be active when RDP is connected AND not minimized.

As soon as i minimize RDP, the GUI is deactivated, so my application can't do its job.

I can't keep the RDP Window open, because that would make the whole point of using a remote machine useless.

How can i keep the GUI active even after closing (not logging off) the RDP session ?

Remote machine is Windows Server 2008 R2 Standard.