Connecting to remote server for backups w/ RoboCopy

I have 2 servers running WinServer2003. One is the main server and one is for backup purposes. The backup server is in a remote location. I am looking at using RoboCopy to copy files and to replicate folder structures from the MAIN to the BACKUP periodically. Its a one-way copy. I have RoboCopy working. Its the method of connecting that i am wrestling with. I have tried using RDC and that works. But it turns out that i remotely connect via RDC from the MAIN to the BACKUP server and then on the BACKUP server run some robocopy scripts (on the backup server) that PULL the files from the MAIN. Sounds kinda circuitious.

I'd like to be able to automate the connection process and the scripts. Whats a better way of connecting from the MAIN to the BACKUP server? Can i map a drive? Use WebDav? VPN? Can anyone point me to some URL primers on this? thanks.