Looking for visual basic code for non-central t inverse

[Stan Hilliard]

I am looking for visual basic code for non-central t inverse that I can incorporate into a Visual Basic program. I am old retiree from 3M company's Statistical Consulting Department. I have a software program, TP414. that can develop a special kind of sequential sampling plan (TSS) for variables, SD unknown.  I believe that the OC curve would be more exact if I were to use non-central t -- as the AQL and RQL are offset from each other. My website is www.samplingplans.com. I would appreciate any advice to point me in the right direction.