Code (Skript):

1. function regex(n: object) :: text:    #<--- use this function
2.     if "%{_n}%" contains ".":
3.         set {_s::*} to split "%{_n}%" at "."
4.         set {_n} to "%a({_s::1})%.%last 2 characters of {_s::2}%"
5.         return "%{_n}%"
6.     else:
7.         set {_n} to a("%{_n}%")
8.         return "%{_n} ? 0%"
9. function a(b: text) :: text:    #<--- ignore this function, its just part of it
10.     if length of {_b} > 3:
11.         return "%a(first length of {_b} - 3 characters of {_b})%,%last 3 characters of {_b}%"
12.     return {_b}

how to use:
(note: Anything can be used within this function, Im using balance of player to show you but you could use a variable.)

Code (Skript):

1. send "Balance: %regex(balance of player)%"

 

Which version of Skript and Spigot are you using?

 

Hmm... Im not sure then, I've never used a Skript version that was like 4 years outdated. Parts of the code I sent might have been introduced in one of the 100 versions that have come out since that version.