Hi there,
This is very doable (I'd say in 3 to 4 days). I have developed ISAPI DLLs and filters in the past and I'm confident we can achieve this.
I'm a Windows and web developer with 10 years experience in Delphi (from v2 to 2006), VB, .NET, PHP and a plethora of other languages and tools. I've dabbled with pretty much everything.
I have worked extensively with internet protocols, including loads of advanced work with HTTPS, SSL, SMTP, web services and more.
Let me know if you're keen on the price and timelines and we can get cracking...
Best regards,
Tinashe