Play By Post Slack-App Help


I'm in the process of building a play-by-post Torchbearer/West Marches style game. We landed on using Slack as the backbone, and I've found two apps to handle the heavy lifting (a die roller and a text spoiler/obfuscator)

The problem, is that I'd really really love to build my own app to handle the Burning Wheel conflict resolution system, but there seems to be a pretty big divide between what the "simple, easy UI, building block, non programmer, make-your-own" app process allows you to do, and actually learning anything and knowing what your resources and limitations are.

Is there anyone out there who knows the process and is willing to help me lay out the bare bones of this thing? I'm a hobbyist programmer at best. I'm not really fluent in anything, but I'm great at breaking down and cobbling together pieces.

What I'm looking for is a slash command that brings up a form with three drop down lists.
When submitted, the app posts a message to the room with three buttons.
When each of the three buttons are clicked, it brings a popup which shows the results from the three drop down lists.