In your example there, twitchnotify already does proper capitalization.
In this case, trying to target a user won't always get a $msgtag, but instead I'd make an API call for it.
alias displayName {
var %j = followUser_ $+ $ticks
JSONOpen -ud %j https://api.twitch.tv/kraken/channels/ $+ $1 $+ ?= $+ $rand(1,1000000)
var %displayName = $json(%j,display_name)
return %displayName
}
When you want to use it, just do $displayName($nick) or anything that needs to go in that spot in place of $nick.