use of extended partition

my main qnx4 is on one of the primary partitions. In order to
overcome the four partitions per disk limitation (I already have three
primary and one extended partition), I have created multiple
logical partitions inside the extended partition. My linux is
installed using those logical partitions (for ext2, swap, etc).
I still have some free space in the extended partition, can I
create a qnx4 type 78 partition? will qnx4 fdisk/mount be able
to use it?