Convert hidden primary partition to logical

Hi:
I used Partition Magic 8 to repartion my hard disk. Now I have ended
up with a structure with two primary partitions (one being hidden). I
want to convert the hidden primary partition to a extended logical
partition. But since the second primary partition is hidden, partition
magic has all the convert and other options disabled for this
partition (it also shows file system as 1F(Hex), but I guess that is
because it is hidden).
Also now I have no extended partition at all on my hard drive.
Any help on how I can convert the hidden primary partition to a
extended logical partition is highly appreciated. Thanks in Advance.
Balaji V