[REQ] Anyone Know How to Do This?

[scorpius2k1]

This person created a plugin for HL2DM which throws "explosive" crowbars and is charging $10 for it. Would anyone here know how to code such a plugin?

Here is the page:
https://foo-games.com/downloads/foos-throwing-crowbar/


Thanks for any help and input. :bacon!::bacon!: