Action - Album Art import through regular expression

Hello.

I'd like to make an action that import Album Art from a file.

Each folder has a cover file with one of the following names.

folder.jpg
folder.png
cover.jpg
front.jpg

How can I import it regardless of the file name?

I tried as follows, which seems wrong.

.jpg|.png

Create an Action Group with 4 "import cover from file" actions, one for each possible file name.
Whichever file exists will be imported.
The ones that don't exist create a warning.
If you don't want to see the warnings, they can be turned off in the "Messages" tab of the Options dialogue.

I don't know for sure but you may try ... o.*g

DD.20140604.1828.CEST

....