Easy way out: Have you tried Octave?
Hard way out: Build a system that has exactly what you want w.r.t. kernel and libraries.
Some might say Linux is a moving target. And that's sometimes good and other times not so good. Open source packages like Octave get rebuilt often because, well, because anyone can rebuild them. Every time something changes in the kernel or libraries someone (usually called a "packager") rebuilds the distribution they maintain. And that can literally be 10's of 1000's of applications!
Commercial software is usually not given out. There are rare cases where some gets given out (like Nvidia drivers) but usually it is up to the company to maintain a compatible version.
Middle of the road ways out:
1. You bought it, right? So contact Matlab and demand an up to date version of the package you already own.
2. Get into Matlab forums and find out just what is incompatible. You might be ok w/the kernel you have. So it may just be the libraries.
Wow, from the looks of it, kernel 2.4.x is circa 2001 to 2003. That's a lot of time rewinding (how old is this copy of Matlab??). You might try web pages like this one: https://old-linux.com/
. I don't think lubuntu existed back then (2001 - 2003). But other distributions did. I think these are ISO images for the most part. So download and burn a disc (probably CD back then) and start installing. Be aware that some distributions (well, maybe not this far back) try and bring in updated versions of code during the installation process. So you might want to keep the computer isolated.
Geez, I just remembered you asked in your original thread about 64 bit systems. Moving the clock back this far may make it hard to find a 64 bit distribution.
Maybe others have better ideas of a good way to go here...