#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?m)\b(([a-zA-Z])\2+)\b|([a-zA-Z])\3+"
Local $sString = "aaa" & @CRLF & _
"aa" & @CRLF & _
"a" & @CRLF & _
"broom" & @CRLF & _
"school" & @CRLF & _
"boo" & @CRLF & _
"gool" & @CRLF & _
"ooow"
Local $sSubst = "\1\3"
Local $sResult = StringRegExpReplace($sString, $sRegex, $sSubst)
MsgBox($MB_SYSTEMMODAL, "Result", $sResult)
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for AutoIt, please visit: https://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm