I have a custom filter form in my site and the form submitted by the filters adds 2 Get variables to the url. However, the variables appear in the form of:
http://example.com/newpage?param1=a%2Cb&param2=c
instead of:
http://example.com/newpage/param1/a%2Cb/param2/c

I have Global redirect clean url enabled and I have pathauto module in my installation and clean url test to checl mysite.com/user/login works fine.

I have tried a couple of plugins eg. query_parameters_to_url but they are not working for that page and I tried adding hook_url_outbound_alter and hook_url_inbound_alter in my custom module but they overwrite all the urls.

Can anyone suggest a way to implement clean urls for somehting like this with affecting the urls for other pages in the website?