Use FreePBX to extend legacy PBX analog extensions

Can I do the following. I want to connect 6 analog extensions from a Merlin Magix PBX to the FreePBX analog line ports and route each port directly to one extension.
I have set up FreePBX and have a Sangoma A200R with 6 analog input ports. Snom gateway and 4 Snom M3 handsets.
The handsets can dial each other.
This is a temporary workaround to connect these users until I deploy a full VOIP solution.
I am a NooB so a step by step would likely be needed

Yes this can be done. But I am not the guy to give you a step by step because I have never done analog lines before but:
Create the trunk (or 6 trunks?) for your pots ports. And set them as from-internal.
Setup the Dahdi DIDs with the extension numbers.
Create your 6 inbound routes with the extension numbers and point the destination to extensions>the same extension number.

Outbound routes will be slightly trickier because by default when you dial out it will always use the first line, but if extension 3 is dialing out on line 1, extension one can’t receive calls. So I would do this by getting the extension routing module, it used to be free, idk if it still is.
Then create 6 outbound routes with the same dial patterns (dialing out and anything else on your pbx) and use the extension routing module to only allow each extension to use its own line.