Custom help topic in VS Isolated Shell

Hello everybody,

         I'm building an application based on VS Shell (isolated) with some packages inside. I'm trying to use my own help service linking the "F1" key to my own url. Using the context bags I was able to add custom keyword to each toolwindow in my package, but I have no idea where tell to the shell to point my URL to search it instead of MSDN. I tryed already to place the "CustomHelp.xml" file inside the "1033" folder as http://msdn.microsoft.com/en-us/library/ms165124%28v=vs.80%29.aspx suggests, but without effects.

Can someone please help me understanding what's weird?

Thanks in advance

G.