SessionId to HINTERNET

Question

Hello All. I'm have the next task: I'm must to write an ActiveX component using C++ ATL. This component must using SOAP client for working with WebService writed on C#. For work with WebService from my component I must to use ASP.NET page SessionId. This ID must be set as current SessionId(HINTERNET) handler for SOAP client. But. C# SessionId it is string type. How I may convert C# SessionId to HINTERNET for using. Thanks. P.S. Sorry for my English.