ASP.net provides several options for posting data to another page or usercontrol within your site, but they all seem to fail within Umbraco (at least that's how it seems when reading through forum posts or trying them myself).

• I've tried using PostBackURL, but it's not-recommended in a couple of forum posts, and I'm confused about how it interacts with URL Rewriting. Basically, I don't know what URL to use to refer to usercontrol Foo.ascx.
  
  
• I've tried using Server.Transfer, but it doesn't seem to work in a handler like Button onclick.
  
  
• I can't use Response.Redirect and put data in the GET query string, because there's a big chunk of data to transfer ... I need to POST.

Is there a recommended way of doing this for an Umbraco site?

Thanks!