With maileater, tags exist that can be used to set a value of a property whilst creating a new incident. That method is described in knowledge article 30793 (https://ca-broadcom.wolkenservicedesk.com/external/article?articleId=30793).
Is it possible to achieve the same via a URL?
CA Service Desk Manager 17.x
All Supported Operating Systems
The properties attribute of the CR object is a BREL.
CA Service Desk Manager is not designed to update BRELs through an URL.
Therefore this is a product limitation and this is not possible.