Hi Joe,
At this point there is no way to get the appadmin working if pub is down.
In UCCX 4.0 this is a sort of limitation and you need to get the pub up to login to appadmin.
The reason for this is that the UCCX 4.0 config resides in DC directory of call manager (If AD integration is not used) and if pub is down the appadmin will not work.
At this point first get the pub working and after that add the subscribers as secondry CTI provider in unified telephony in UCCX.
HTH
Rajiv