If it's not apparent, we're pretty busy with other things in life, especially Megiddo.
Are DarkRP jobs the exact same as 'Teams'?
If so, you could use the
OnPlayerChangedTeam hook on the server to run your command on the client.
If they aren't teams, then you'd have to find out what DarkRP uses on your own.
If it's some player variable that changes, then run a timer to look for it..if a match, run client command to change.