Unfortunately, our geomapping functionality is quite limited at the moment as our first intention was to provide the compliance between three different mapping services and their respective APIs. However, we do plan to enhance the geomapping functionality and provide client side API for it, but unfortunately there is no date set for this task yet.
The option you have is to use your own geomapping control on the public side, and use the Events.Geomapping_Data meta field to extract the geo longitude and geo latitude entered by the user. This, however, would not be a trivial task.
I am sorry for not being able to help you further at this moment. Let us know if there is anything else we can do for you.
the Telerik team