#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?i)\b_*([a-z])[a-z]*(?:'s)?_*\b[^\n\w]*"
Local $sString = "Halley's Comet" & @CRLF & _
"First In, First Out" & @CRLF & _
"The Road _Not_ Taken" & @CRLF & _
"O'Brian's Dog"
Local $sSubst = "$1"
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