Sorry, I'm afraid that is not possible. We don't have the source code. When modding a BIOS, I can only patched the binary file. I still rely on the existing code in the BIOS (and also hardware compatibility) for any unlocked menu to work. Most likely the Bus Speed Override doesn't work because it is locked on hardware level, e.g. TME locked. If this is the case, will need to do "pinmod" to
unlocked the Bus Speed Override.
To find what PLL/Clock Generator your notebook have, you will need to examine the motherboard. Or if you have schematics of your notebook, it will help a lot.
Then, after identifying the PLL/Clock Generator, you can use SetFSB to check whether TME is locked or not. You can refer to this post (see
2. How do I check TME_READBACK to see if I can overclock my PLL with software?):-
http://forum.notebookreview.com/4998927-post1.html