To determine the distance between two objects you can use the distance command;
Object1Name distance Object2Name
Will return the distace between the two objects.
If you wanted to set targets at certain distances, you'd use the setpos command,
TargetObject Setpos [(Getpos Player Select 0) +100, Getpos Player Select 1, 0]
This line would set the named target object 100 metres east of the player unit. Its easier if you want to set the distances in either north, east, sourth or west directions as you can just change the value of the offset (the +100 in this case) and move it to either the select 0 (east/west) or select 1 (north/south).
Moving it off in any other directions (north-east for example) would still be simple, it just requires some trigonometry.