You can get a small Behringer mixer for about $50 with USB, connect the output of your module to it and use the mixer as an audio interface. the audio from both the computer and your module should be coming out to the headphone out of the mixer, basically you have to change your sound settings so that the sounds from your computer come out of the mixer, not sure if they will come through Skype but you can test...you can get a Focusrite audio interface for about $100 for better results, I think both would work the same way. I unfortunately am in the middle of the ocean deployed in the Middle East so I am unable to test it at this moment, but I am sure a quick YouTube search will show you how to connect your drum module to Skype.