Unfortunately we currently do not have a way to wire up that sort of linkage since forms are very fluid and that sort of linkage would be very brittle and hard to maintain.
However, you can set default values on your request forms in order to "pre-fill" some of the data on a form and you can put links out to the service where the user can make the request. Users will be required to log in in order to make the request.
What sort of linkage are you looking to make? Is there a way you could utilize the API to create requests programmatically from a link?