Backup Partition for CloneZilla?

[hhtmp88]

Dear all,

I have partitioned my 320GB drive into the following partitions:
1. boot partition: /boot ( 100MB ) ----- /dev/sda2
2. Program Partition: / ( 15GB ) ----- /dev/sda1
3. Data Partition: /home ( 240GB ) ----- /dev/sda3
4. Backup Partition: ?? ( 40GB ) ----- /dev/sda6
5. swap partition: swap ( 5GB ) ----- /dev/sda5

since the 4th partition is for backup purpose, I have not mount any directories to it during Mythbuntu setup,
-> but then, it is not accessible
-> so, how can I backup the program partition (using CloneZilla) into this backup partition?

Thanks for any kind of help!
Rgds,