How to use cryptsetup and device mapper

Desire to utilize the subject utils to perform the function of joining,without encryption=none, two loop devices as described below:

dmsetup? or cryptsetup? create knoppix <<EOF 0 991838208 linear /dev/loop0 0 991838208 991838208 linear /dev/loop1 0 ....The numbers indicate the size of the loop devices(split knoppix.iso's)

It is my understanding that this entry should generate a block device called knoppix. It uses device mapper to "merge" the contents of the loop devices.

Perhaps this step is followed by an execute command? Perhaps something missing in the kernel 2.6.11?

Any help will be appreciated!!!