#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "/img/([0-9a-fA-F]{2})([0-9a-fA-F]+)$"
Local $sString = "example.com/img/fe5afe0482195afff9390692a6cc23e1"
Local $sSubst = "/content/img/$1/$1$2"
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