#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?i)(?i).+FE00(.{20}).+"
Local $sString = "0x00FFFFFFFFFFFF000DAF21170000000005130103802716780A06359E56529829145054000000010101010101010101010101010101012F2640A060841A30302035007ED710000018000000FE004E3137334647452D4C32310A20000000FE00434D4F0A202020202020202020000000FE004E3137334647452D4C32310A2000C3"
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