Any Partner can use Centrex Flash to transfer to an external number. This requires services from your phone company.
Release 6, 7, and 8 have the ability to set extensions for Remote Call Forward, so calls transferred to specific extensions will follow the forward to the outside number.
Partner ACS requires a Remote Access Backup and Restore card for remote programming. R7 and R8 have a serial port that you can connect to an external modem, and set up for remote programming.
If, by remote access, you mean dialing in and back out, no that is not a feature of the Partner.