Hi effectively new to modding, created a fortified 188 trading post with sniper spots.

However I was wondering what would be the easiest way to have each sniper stationary until an enemy is within range, when they can move, before returning to the base position?

any help greatly appreciated as I imagine it's a simple answer though so far I have been unable to do so

It depends on where you want the snipers. The easiest method is to place a marker for each snipe and set up a package for them to travel to it. Alternatively, you can set up sniper nests that are not accessible, then navmesh them so the snipers can sandbox in the nests but can't run off (markers on the nests can also doubly ensure that and allow you to set the range of their sandbox package). For the second method, if you have GECK for FO3, you can check out the 'Canterbury Commons Guards' mod to see how I did it. The link is in my sig.

Thanks very much Ripple, I think I will try out the first option as I have them currently linked to by a walkway on top of a wall, allowing them to find a better angle when under attack before returning to their position.

I didn't get FO3 so sadly can't check out your mod and ideally I'm trying to have them stationary not sandboxing but may toy around with that as well

many thanks