#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?m)(?:\b|(?<=[a-z]))(?:ShFrm|LgFrm|Auto)(?=[A-Z]|\b)"
Local $sString = "ShFrmLgFrm should be replaced Automatically" & @CRLF & _
"Auto" & @CRLF & _
"AutoLgFrm"
Local $sSubst = "<match>\g<0></match>"
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