I can't get a CFB/NA to program using the 604 command. 601, 602 commands work. 603 & 604 don't
The input takes a 3 digit DN destination then a 4th digit??. I.ve tried using the * with a 2 digit delay time, That doesn't seem to work either.
Any suggestions.

From your DN button, #604+target extension+SPD button+delay time in seconds+Redial. If you don't have a system speed dial button programmed, you can use * but if you have one programmed on the phone you will need to use it.