search for: hypergeometric2f1

Hi, I'm an R newbie and I've got a question regarding a certain function in R. I need to calculate values of the hypergeometric 2f1 function (hyp2f1 in cephes math library, Hypergeometric2f1 in Mathematica) and I'm wondering if anyone has tried to implement it in R or S-Plus. If not, what would be the prefered way to do so? Should I rather try to use an external C module or implement it in R directly? Thanks for any hints! Best Regards, Daniel P.S.: This is my first posting t...