IIS / SSL / Site Security / Multiple Sites

Have a question about an IIS server with multiple commerce web sites and
single SSL certificate

Here is the scenario (single server, single static IP)
www.TheCompany.com this top level company website has the SSL certificate

www.Product1.com \\CompanyServer\c\web\Product1
www.Product2.com \\CompanyServer\c\web\Product2
www.Product3.com \\CompanyServer\c\web\Product3
they both have their own shopping cart, etc. and their own "payment.asp" or
"payment.aspx" pages, with their own theme.

But I want to handle the credit card number entry screen with https:\\ but
with the existing SSL certificate for TheCompany domain, without buying Wild
Card cert and without dealing with many certificates. How can I do that?

Second acceptable solution is to redirect from Product1.com to
Product1.TheCompany.com/payment.asp, but it causes redirction related
security problems.

Is there any way of solving this issue without changing the URL away from
Product1.com with Frames or some other way so that I can use the single
Certificate. I believe some of the Hosters are doing this kind of stuff.

Any ideas about how it can be done? Thanks a million