ISAPI communication

We have an ISAPI server, to which we would like to transfer some data. Usually, it is done just by calling "url\dllname?function&param1&param2&...". The problem is when we want to transfer some binary data to the ISAPI. We used InternetOpenUrl up to now, but it takes strings, so it is not good for binary data ('\0'...).


What is the best way to transfer binary data to the ISAPI?


note: We don't mind override the 'HttpExtensionProc' and 'CallFunction' of 'CHttpServer' class in the ISAPI dll.


Thanks,


Oded.