Perhaps you tried the regular expression before it was corrected? The original version had a typo and I apologize for that. The code above (corrected as per AnomalousMonk) does indeed extract just what is between the parenthesis. However, it can't be used just by itself. It has to be inserted into a loop that reads in each line. A lot depends on exactly how you do it.

If you are having trouble getting it to work, perhaps you should consider adding an update to your original question and post the code where you are using the regular expression (or just post it in reply to this node). Then we might be able to see if there are other issues besides the choice of regular expression that are causing problems.

Best, beth