Loadrunner Correlation : Dynamic left boundary and right boundary in web_reg_save_param

You can use following regular expression attributes  in your loadrunner script to deal with dynamic left or right boundaries :-

1. LB/DIG - This attribute interprets the # sign as a wildcard for single digit. eg:-  "Error5##" matches for "Error500", "Error501" till "Error599".
2. LB/ALNUM - This attribute interprets the ^ sign as a wildcard for single US-ASCII alphanumeric character.
3. LB/ALNUMIC - This attribute interprets the ^ sign as a wildcard for single US-ASCII alphanumeric character, this regular expression is case insensitive. eg:- "Er^^r" matches for "Error", "ErRor", "ErrOr", "ErROr", "Er12r", Err1r" etc. 
4. LB/ALNUMLC - This attribute interprets the ^ sign as a wildcard for single US-ASCII alphanumeric character and lower case.  In this case "Er^^r" will not match for "ErROr", "ErRor", "ErR1r" and others with an uppercase alphabet present.
5. LB/ALNUMUC - This attribute interprets the ^ sign as a wildcard for single US-ASCII alphanumeric character and upper case.