This looks like a simple dual-boot of DOS and Windows XP.
Just search for installing DOS beside XP and you will find many solutions.

The easiest way:
1. Install DOS on a primary partition
2. Install XP on an extended partition, the XP bootloader will now include the option to boot the DOS-System like in the video

But be careful, if you delete the DOS partition later, your windows XP bootloader will also be deleted, because it's on the primary disk.

you want to Boot win98 into Dos-Prompt?

Hello members,
How to launch windows program in DOS at OS selection screen during boot?
To share the concern better, I have made a video taken from someone's computer and wish to setup same at mine. Kindly have a look at the following link:
https://youtu.be/YAO9OGsNBUw

Please guide, advance thanks!!