I wish to do a so-called "bare metal backup" of my hard-drive using Clonezilla or similar software. The only problem is that I would like the destination of the backup to be an external hard-drive which has been encrypted using Truecrypt.

Since Truecrypt isn't included in the Clonezilla LiveCD, the external hard-drive obviously can't be mounted so easily. Any suggestions on possible workarounds or other software?