ROM Hack How do you use the GBA MP2K MEMACC command in a sequence?

[biolizardshadow]

I am trying to understand how this command works and what it can do? This document Summary of GBA standard sound driver (MusicPlayer2000) | VGMDocs (loveemu.github.io) explains more on how it works, however, I still don't know how to use it properly. For testing purposes I put this into one my finished songs "mem_set, 0x03000A60, 3". My goal here was for the gba to write the number 3 to that specific address in ram, however, that is not happening.

Any help here would be great!

[Edit, I forgot to mention that information pertaining to this command is found near the bottom of the page I linked above]