DOS Extended partitions under SCO-UNIX

[some1]

Dear freands, Hello

How can I use DOS extended partitions under UNIX that they are created after installing UNIX? as below:

I bouth a new 40G Hard drive, and first made in it a DOS primary partition sized 2G, then a SCO-Unix 5.05 partition sized 1.2G.
I then created an Extended DOS partition with 2 logical drive, and when I wanted to use that two DOS logical drives under UNIX( with mount command: mount -f DOS /dev/dsk/0sD ) the mount command responded me: No such device?

Thanks