This is not supported on v2 of Nemosminer. Download V1 (see first post) and edit the .bat file. You will see something like 0,1,2,3,4,5,6 at the top of the file, which represents the GPU number.
Yeah I was able to get it working now that I have the V1.7 - I wonder if there are any plans to adding this to the v2 given the fact I run two different GPU's none of which are part of the 4 files already pre-set there.
Thank you for the help.