i have no idea, sorry
listen, try this:
press "X"
and it will show you the current map's code, for example, in Slum, the map code will be: "AR0400"
however, if you go in the Copper corrent, and press X, it show you AR0402
you got my point? press X at underdark, it shows you the current map code, then mess around with the last two digits, you will get to where you want to go.