#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?i)(id='.*?') (srcDocId='.*?')"
Local $sString = "<document id='3316200' srcDocId='http://ecx.images-amazon.com/images/I/61A9A0fmN7L.jpg'</document>" & @CRLF & _
" <document id='3306829' srcDocId='http://ecx.images-amazon.com/images/I/71sQDUoJbmL.jpg'</document>" & @CRLF & _
" <document id='2406251' srcDocId='http://ecx.images-amazon.com/images/I/71j7ISxAOdL.jpg'</document>" & @CRLF & _
" <document id='2534144' srcDocId='http://ecx.images-amazon.com/images/I/71VXMXcrg2L.jpg'</document>" & @CRLF & _
" <document id='3417415' srcDocId='http://ecx.images-amazon.com/images/I/71Ymoo32gVL.jpg'</document>"
Local $sSubst = "$1 $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