Custom Download Plugin - HELP!!

[rjmjr69]

Hello, I am trying to make a custom plugin for my own forum.

Me and some friends use Vbulletin on our own website to make and share custom Android apps.

I want to make a new plugin that replaces the existing attachment system.

I want to allow more kinds of files, and allow easier uploading and downloading of .exe and .apk files. (Think Dropbox links)

I have worked with PHP for a long time and made many custom wordpress plugins, but I am at a loss on how to get started on creating one for Vbulletin.

(NOTE - I consider this a "programming" question - if this is the wrong place to post, let me know and I will move it to the correct area)

I'm not sure which is easier - modifying the existing the attachment system - or make a plugin to do the work.

We are also using the Vbulletin CMS - so we have blogs too - and I noticed that the attachment system is different there. So maybe a plugin will be the best.
I've noticed that the posting "box" for blog posts, forum posts, blog comments, and forum replies are all slightly different >_<

I am also completely lost when it comes to Vbulletin hooks - I am not 100% sure which ones I need to access in order to use my plugin.

I have poked around enough to create a "Hello World" level plugin and custom BB code. But I am a bit lost when it comes to creating something as complex as a custom PHP based attachment system and hook it into the Reply boxes across the board.

I may be getting ahead of myself, but I would also like to make a BBcode that will call a direct link to the downloadable file e.g [download]my-new-app-apk[/download]

I don't expect everyone here to hold my hand through this entire process - but after checking several forums posts over a few days, I am still lost. I would appreciate some direction - maybe a tutorial or some resolved posts. Perhaps even some choice keywords to help me search for a solution.

I also plan to keep this thread going with my findings, so the next newb can use this as a roadmap.