I assume you are referring to audio line-in volume control and lerft-right balance...
If so, then check out this thread:
http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=135&HOID=506500000008000000D83A0000&UCATEGORY_0=_49_%24_6_&UCATEGORY_S=0
Look at the info near the bottom from Paul S & Spectre. They talk about "winmm.dll"
-cheers-
JLV