301 redirects to migrate site to Code Igniter

Question

Friends,

I am working on a website in CodeIgniter. I want to launch it soon and after launching I don't want to loose the current indexes in Google. So I want to permanently redirect the existing website's URLs to the new SEO friendly CodeIgniter URLs.

Existing website's URL: www.myapp.com/main.php?{param1}={value1}&{param2}={value2}&page={3}

I want this request to be permanently redirected to the below URL (using htaccess 301 redirect): www.myapp.com/process/page/{param1}/{value1}/{param2}/{value2}/pagination/{3}

Note: I used { and } symbols to denote the values to be reused in new URL.

Please help me asap!

Thanks in advance!