phpBB integration

Hello I have a website where phpBB 2.x version is installed, integrated and working fine. We have also installed the latest version of phpBB 3.x in a separate folder what I need is, there are about 3-4 pages where phpbb latest version needs to be integrated. Register Login Add Trip (a few forms fields to add in db. it should add the records as a post in phpBB) Home Page (fetch latest few topics on homepage.) Please let me know how much will it cost and how long? This is urgent project. Regards Ali