It could be that you're looking for a folder that is usually hidden and you're looking in the wrong location because of this. Are you looking in the Library folder from your Macintosh HD? If so, that's the wrong Library folder. You usually can't see your user's Library folder or it's contents.
To show hidden files on OS X Mountain Lion, just open Terminal and copy (not sure if this is the same for Lion but you can give it a try):
defaults write com.apple.finder AppleShowAllFiles TRUE && killall Finder
You should be able to see the hidden folder now. Click on your username in finder and then Library/Workflows/Applications/Folder Actions
When you want to hide hidden files again, just type the same command, but change TRUE with FALSE