I have created a sample project that implements your idea. RadDocks are dynamically created in a WebControl (the contents of the DefaultCS.aspx file of "My Portal" example are in the Master.ascx file of my project), which is called in other WebControl (CallMaster.ascx). This last web control is called on the .aspx page in a RadSlidingPane. The submit button of the ExchangeRates.ascx is making an AJAX post back, the same way as in the online demo.
All the best,
the Telerik team