If the configuration is the only thing that needs to be backed up, you can use a tftp/ftp server to pull it off.
The commands would be,
if tftp,
copy startup tftp:
if ftp,
copy startup ftp:
No need to be onsite as long as the FTP/TFTP server is already setup and available. It can be done remotely if you have access to the route via telnet/ssh.
This can be done to transfer any files that may be on the flash, including the IOS file.
The command is discussed in more detail in the following link.
http://www.cisco.com/en/US/docs/ios/fundamentals/command/reference/cf_c1.html#wp1064741
For general information on navigating the IOS CLI,
http://www.cisco.com/en/US/partner/docs/ios/fundamentals/configuration/guide/cf_cli-basics.html
-Felipe