Need help with contextual substitution for my font

[Ahzoh]

I've tried reading some guides on here but I can't really wrap my head around these open type features. And I can't really extrapolate what little I could figure out to my own font since they all deal with the Latin script cursive.

Could somebody show me how to make it so that an input letter switches to isolate, initial, medial, and final forms within the context of my font?

[Erwin Denissen]

There are numerous people who use our font editor to make Arabic fonts, so maybe others respond here as well with more suggestions.

Do read the part about init, medi, and fina at the end of this topic within the user manual:
Automatic OpenType Layout Features

Also make sure the glyphs have correct names.

[Ahzoh]

Oh, my glyphs are not assigned to the Arabic codepoints but on Latin codepoints (I plan on switching them to the Private Use codeblock), which the .init, .medi., and .fina do not work with.

[Ahzoh]

Well, I figured out how to make chained contextual substitutions and i figured out how to get the forms to worth with each other, so now i have this: