Photocomix, I think I have found a way to extract all of the comment lines from a single script in Notepad++, which consists in eliminating all the other lines that are uncommented by means of the RegEx functionality.
Once you have opened the script with Notepad++, launch the "Replace" window through "Search -> Replace..." and, first of all, activate the "Regular expression" radio button placed at the bottom of the window in question, then copy the following string and paste it to the "Find what" text box (sembra ostrogoto, lo so!):
Then leave the "Replace with" text box blank, disable the "Match case" checkbox and enable the "Wrap around" checkbox.
Lastly, click "Replace All" and, in case, save the outcome to a new file with a different name than the original one in order to keep this unchanged.
I have tested this method on one of my scripts and it seems to work correctly. Also, since it should work regardless of the contents of the particular text loaded, I suggest you record the steps I described in a Macro, so you will have the possibility of reproducing such type of manipulation every time you want by simply playing the saved macro.
P.S.: in case the source code to handle is written in Python, this stratagem should still be valid, provided that you use the following regular expression in place of the one I posted above referring to Script-Fu instead: