CRM External Link issue

Suggested
Dears,
Upon navigation to an intrinsic CRM entity such as lead, case opportunity from an external link sent via email for example
The link uses SessionFind method of eware.dll to get the current logged in session SID i.e. "">localhost/.../SessionFind
How can I use such functionality to be applied with custom entities using ASP pages, noting that the link to be sent via email is sent to a CRM user that is already authenticated to CRM