I feel like I've researched this to death, but I'm sure it must be possible (certainly considering the scope of Slack's customisation).The general concept would be to allow a user to type in a string of a predetermined pattern, then that could be converted.An example would be like the Giphy plugin, which takes /giphy {$string}.gif and dynamically alters the output by posting an image.The intended output would be so you could type in something along the lines of #12345 (or even /foo 12345) and this could produce a fully formatted string.For example:/foo 12345is changed to output http://foo.bar/p=12345I'm simultaneously skeptical that it can't be done, and that it can be done!  I'm hoping that someone has managed a solution that wouldn't pointlessly use hooks or bots (as generating a new message wouldn't really be very slick at all).
Can Slack convert/substitute strings into another output?
slack