Match-variables are set implicitly by this method.Use normal regex for pattern. The group operator capures parts of the regex
to put into a variable.
Sample: msg="ab1234cd"var="" regex="ab(.*)cd" .. no variable will be setvar="userid" regex="ab(.*)cd" .. variable userid is
set to "1234" var="userid" regex="ab.*cd" .. variable userid is not modified - missing group expressionvar="userid,poscode"
regex="ab(.*)([cd]+)" .. variable userid is set to "1234", variable poscode to "cd" var="userid,psocode" regex="ab(.*)cd(.*)"
.. variable userid is set to "1234", variable poscode to "" - empty group match