Hello,
CertTech, L.L.C. (Leawood, Kansas, USA) has written code in both Visual C++ (the Server side) and in Labwindows/CVI 5.5 (the client side) for the very tasks you are trying to solve. Most of our work is proprietary to our client, but if you are still searching for solutions in this area please send me an email at drbarbour@certtech.com and I will prepare some non-proprietary examples for you.