VerthashMiner how to use only 1 gpu in an System with a Nvidia and AMD GPU?

self.vertcoin8m ago
To be clear i have a Gtx 1070 and an Radeon 280x, but i only want the 280x Mining Vertcoin whie the 1070 mines another coin. As i understood it the generate\_verthash\_data.bat optimizes the Rig at their current settings to get the best Hashrate, but i guess it will then Try to optimize it for both GPUs so if the 1070 is missing it crashes.