Put one tar.bz2 file to another tar.bz2

Hi experts,

I have two tar.bz2 file,:
a.tar.bz2 and b.tar.bz2
I want to put a.tar.bz2 in to b.tar.bz2

eg: b.tar.bz2 only have one file named "b.c" contained
I want it contain "b.c and a.tar.bz2"

I don't want to decompress the b.tar.bz2 to achieve this, I try with "cat a.tar.bz2 >> b.tar.bz2" but it can't achieve this

Lei

tar -Af b.tar a.tar

This you can achieve in tar by using above command.
Can u not decompress bz2 and use above command and compress bz2.

Hope someone can add on this.