AFAIK , after searching on internet, the only rw compressed file system is jffs2 on flash, which can be used only with internal flash of the Z not on sd or cf.
Hence the interest for uclx for compressing exe on the sd or cf.
you have instruction for creating an image file
in this thread it might work on samba or nfs (I didn't try any of these things)
If this work you should be able to copy some of these images to your cf and
mount it to the same mount point but you'll have to issue the mount command by hand anf not put shortcut in fstab.
There is a limitation in the number of image you can mount (loop device)