Glad that you managed to save the settings Paul. I'm not sure what's happening with the A/S. I don't have the a7C to check unfortunately. It should be very similar to my a7III though as they use the same menu system.
In my menu I just see a large P which I guess stands for Programmable. Then depending on the focus mode set you will see either AF-S, AF-A, AF-C, DMF or MF. Is this what you mean? If not, maybe if you can send a photo of the back of the screen where you see the A/S as that would help me.
To change the settings you just need to make sure that the mode dial in set to whichever programable mode you want to change, so 1, 2 or 3. Then change your camera settings. So if you wanted to use AF-S hit the Fn button and change the focus mode to AF-S.
You now need to register the settings change otherwise it won't save them. Find MR 1/2 Memory in the menu. Make sure that either 1,2 or 3 are highlighted depending on the one you want to assign, then hit the button in the middle of the control wheel. It should say "Registered" when the settings are saved.
You should now be able to change to other modes on the top dial but when you come back to mode 1 your settings should be as programmed.