[otrs] Survey On-Demand

How can I get the Surveys out there for any one to take at any time. I would like to include a link in the "Close" response that would take the user to OTRS to take the survey if they wish. Also, we would like to be able to send out annual surveys by email with a link back to OTRS. I have found how to send the Master survey every so often, but I would really like it to be on demand as well. TIA Daniel