UR44: How to switch windows audio between Mix 1 & 2?

Hi there,

I just got my UR44 and everything works well with Cubase 7.5.

Since I have two monitor pairs connected to my UR44 I also want to use them for the playback of usual windows audio (e.g. Winamp, VLC). Therefore I installed ASIO4All which allows me to play back windows audio on Mix 1 of the UR44.

Nevertheless, I cannot find a way to switch to Mix 2 - even using dspMixFX. Is there a trick to achieve this?

Thanks for any ideas in advance!