There is a 68M to 50F adapter that can be purchased, would this be the type of thing that you're after:
http://sine.ni.com/apps/we/nioc.vp?cid=11818〈=US
If you're interested in making your own adapter then the user manuals should give you the required pinouts.
PC-LPM-16pnp manual:
http://www.ni.com/pdf/manuals/320287c.pdf