Login to vTiger customer portal via url

I have an application, “CC”, on a separate server which my customers use. I would like them to be able to click an icon in “CC” which generates a url like [login to view URL] and automatically logs the user into the vTiger customer portal. The encrypted password is easily decoded with base64 and openssl This mechanism should be in addition to the standard [login to view URL] mechanism, which should work as normal. The portal login mechanism is fairly simple - I do not expect this to be a difficult project.