How to make an ISO image of only the Windows (iso9660) track of a hybrid CD-ROM?

I have an old hybrid CD-ROM made of two track : on Windows only the ISO9960 track is visible and mounted, and on macOS only the HFS track is visible and mounted. This is how the CD appears in the Terminal using df and diskutil:

iMac:VINTAGE ouafouaf$ df -k
Filesystem                        1024-blocks       Used Available Capacity  iused               ifree %iused  Mounted on
...
/dev/disk4s1s2                         330576     330576         0   100%       99          4294967180    0%   /Volumes/Dragor le dragon

iMac:VINTAGE ouafouaf$ diskutil list
...
/dev/disk4 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:        CD_partition_scheme                        *778.1 MB   disk4

I want to make an ISO image that is usable under Windows (XP). I tried to with dd and different attempts:

dd if=/dev/disk4s1s2 of=Dragor1.iso bs=2k
dd if=/dev/disk4     of=Dragor2.iso bs=2k
dd if=/dev/disk4s1   of=Dragor3.iso bs=2k

- case 1: I obtain a file of about 330MB, which I can mount on macOS but not on Windows. It appears that this is only the HFS track. Note that the image I get with Disk Utility (.cdr file) is about the same size - case 2: I obtain a file of about 760Mo, which I can not mount at all - case 3: I obtain a file of about 660Mo, that I can mount on both macOS and Windows (so it contains both tracks) So far so good (even if I don't really understand the meaning of s1or s1s2)... But for the use under Windows I don't need the HFS track. I have many images to create for using them in a Windows XP virtual machine, and I don't want to allocate too much disk space: how can I make an ISO image of the ISO9660 track only ? I tried making the image directly under Windows, but the tools I have tried all make an image of the entire disk, HFS track included.