General Support: Including plogger in a SPIP page : page=mypage variable problem

Hi all,
Thanks for this nice script, I'm trying to use it in a CMS named SPIP (a french product!). This CMS serves the page named 'mypage' according to the page variable, so urls look like this :
http://www.mysite.com/spip.php?page=mypage

I created a 'gallery' page with the includes (header, body, footer) as recommanded in the readme file. So I can access my gallery and see the collections with url :
http://www.mysite.com/spip.php?page=gallery

Till there, everything works well. BUT, as variables are lost when plogger is asked for a page, the url to see a collection is :
http://www.mysite.com/spip.php?level=collection&id=2
but the url should be :
http://www.mysite.com/spip.php?level=collection&id=2&page=gallery
with the 'page=gallery' variable defined. Otherwise the SPIP CMS is blowing up.

I'm looking for a global url-changing solution, I don't want to edit each .php file nor each themes file... just imagine how many links I have to modify!

Thanks for your help!
Laurent