I think I have this in the right place, so here's what I'm trying to do, and I'm not sure what the best option is:

I'm finishing up a series of 4 websites: one primary and three secondary, each one on it's own domain. The company wants all sites to direct to the primary domain site, which will then link back to the others (each site relates to an organization in another state).

For example:

I want to go to www.state1.com and get redirected to www.primarysite.com, then that site will have a link that will go back to www.state1.com/index.php, and from there the site works normally (all links to that site's main page will reference index.php, not back to the primarysite.com).

I have access to cPanel for each of these domains. I considered making home.php the default page, have that page redirect, then link back to index.php. But I'm hoping for a cleaner way to do it. Anyone have a thought? And did this even make sense?