How to load a Web User Control inside a WCF service and returning the result?

I need to write a WCF service which is responsible to load a Web User Control and return the html result. My Web User Control has html controls, server controls and javascript.
How is it possible to do this?
(I know we can Load a WebUserCotrol on a Page using Page.LoadControl(...) but I have to use a WCF service which will be called using a javascript from the client)
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