So do you want specific stations to dial out only on the analog lines? If so the easiest way to do this is to make new routes and add into the routes as a Route List, PRI route first, then the Analog lines second, and use COR programming to make the sets call out on the analog route.
For example...
Route 1 - PRI calls (COR Group 1 - members include COR 1)
Route 2 - Analog lines (COR Group 2 - members include COR 2)
Route List 1: 1st Choice - Route 1, 2nd Choice - Route 2
Digit String: 9X - Route List 1
Then assign the phones will use the PRI a COR of 2, and the phones to use the analog lines a COR of 1.
This is extremely simplified, but hope you get the idea.
Of course, you could just make a new leading digit (like 8 ) for the analog lines, and program duplicate ARS with 8 instead of 9 and all the 8 routes use the analog lines, then just tell people to use the analog lines, dial 8+ and to use the PRI dial 9+.