Random Zone Grids Moveing

Does anyone have any random code to insert in
the grid path so that say....
if i wanted all my monster from one zone to randomly travel
from guk entrance to sro entrance that I could mass
insert to get all my npc's for that zone to randomly travel this area.
thats just an example say you want all the tadpole to randomely travel all over swampofnohope.,

I have found #gassign 5142 to work best so far but there is no real standard.