You may run into trouble with the results being cached. If that’s the case, try calling both the snippet and pdoResources uncached.
An alternative would be to call a snippet higher up on the page that set a placeholder based on the URL param and use a placeholder tag for that placeholder as the value of the &tpl property. That might avoid any caching issues.
In any case, the same Tpl chunk will be used for all resources aggregated by pdoResources. I assume that’s what you want.
thx. I Try to work with bobray’s solution. On my first try it loads every time the same TPL.
Tomorow with a pack of Sleep, i will try it again. Thy So much, i will give you a feedback