#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?m)((?:\d{2})(?:\:\d{2}){2}).*?\[\s(\d+).*?\[\s(\d+)"
Local $sString = "Line 394 : [21:44:07 Oct 12 Fri] @0x3924004E|JVM| Free Memory: Heap [ 2368340/ 6291456], Native[ 7299824/32505856]"
Local $sSubst = "\1,\2,\3"
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