PageOverlay with Alternation

Greetings All:

Does anyone know of a way to accomplish the following:

I have a source document ( 8.5 x 11 ) 15 pages

I have a template document ( 11 x 17 ) 15 pages    

I need to overlay the source document onto the template and specify different x/y coordinates for odd and even pages.

( this will establish gutters for binding, etc )

I have used alternation with PageContent, but don't see a way to use it with PageOverlay

Any help and/or example DDX is greatly appreciated

Thank You

Mark