What would be the best approach to using perl to access a TLS protected microsoft technology based web portal?

I'm writing additional code to allow schools in Alberta, Canada to access the provincial Education Dept running this portal. My software, Open Admin for Schools, (GPL perl based) can easily access the next provinces system (Saskatchewan, Canada) using SSLeay (along with OpenSSL).

However this is a much tougher nut to crack. I can easily handle the xml and soap calls, etc. The problem is how to get in the front door. I have all required digital certificates, etc and have a demonstration app (written in Visual Basic), which works fine. However, I need a server app with which to do real work to synchronize student school registration, etc with Alberta Education

Any suggestions most welcome!