Hello,
Take a look at the NI Measurement Studio Help at Start >> All Programs >> National Instruments >> Measurement Studio. Once this is open, search for "scale members." The functions you will be interested in are the RangeMapScale, Linear Scale, Table Scale, and Polynomial Scale Members. This document has all the information you will need to create and save a custom scale in VB.NET.
I hope this helps. Please let me know if you have any further questions.
Regards,
Sean C.