Save your expansion to /scripts/plugins/AFBaseExpansions/
Too lazy to write a proper tutorial so just follow this reference image:
line 1 -> holds the class
lines 3 to 6 -> function thats called from AFBaseExpansions.as, remember to distribute this function name with the expansion post
lines 8 to 16 -> actual class, extends AFBaseClass
lines 18 to 23 -> namespace for the expansion, commands n stuff go here