#include <StringConstants.au3> ; to declare the Constants of StringRegExp
#include <Array.au3> ; UDF needed for _ArrayDisplay and _ArrayConcatenate
Local $sRegex = "(?m)([3-9][0-9]{3}|2[1-9][0-9]{2}|20[3-9][0-9]|202[1-9])-[0-9]{2}-[0-9]{2}|2020-1[0-9]-[0-9]{2}|2020-09-2[2-9]"
Local $sString = "2019-09-22" & @CRLF & _
"2020-08-22" & @CRLF & _
"2020-09-21" & @CRLF & _
"2020-09-22" & @CRLF & _
"2020-09-23" & @CRLF & _
"2020-10-22" & @CRLF & _
"2021-09-22"
Local $aArray = StringRegExp($sString, $sRegex, $STR_REGEXPARRAYGLOBALFULLMATCH)
Local $aFullArray[0]
For $i = 0 To UBound($aArray) -1
_ArrayConcatenate($aFullArray, $aArray[$i])
Next
$aArray = $aFullArray
; Present the entire match result
_ArrayDisplay($aArray, "Result")
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