Some people like to write out dialogues or even scripts in MS Word. Also, if you use Outlook, it may use Word as your email editor, if you email anyone any scripts. By default, Word very helpfully changes all your quote to smartquotes, hyphens to m-dashes, etc. which is great and looks nice until you paste it into an AGS script, where it causes havoc. You can turn of this feature under Tools->AutoCorrect options but it can be useful sometimes.
What to do?
Well, dump your AGS script to a file, download mswordfix.exe (http://ssh.me.uk/progs/mswordfix.exe) and then drag-and-drop the dumped file onto the exe. It will rename the old file as .bak and create a new one with the same name with the funny chars (mainly - no guarantee!) fixed. Reimport the dump file and Bob's your uncle's special friend.
Thanks to DeMoronizer and Perl2Exe for their help!
You can also copy the script into notepad after writing it in word and then copy it into AGS.
I don't think that notepad fixes as many things, e.g. it doesn't do smart quotes.
Sorry I misunderstood your first post.