You can add as many get-parameters as you need to this method. See the Constructing pagenav section.

Anyway, that's not what you want, then. Although I don't quite understand why you would want to hide away the search parameters. I find that highly annoying as a user, since search results can't be linked to (like in vb with it's cached searches). In my opinion, there's good cause why for example Google does not do that.