Disk Image became an alias

Hello. I recently tried to use spotlight to search for a disk image. When I clicked on the disk image in the list, it told me that the alias couldn't be opened because the original item couldn't be found. I wasn't sure why it was talking about an alias, but I chose to select a new original, then navigated to the .dmg through finder and selected it. Now when I navigate to the original file, OS X says that it's an alias, and that it doesn't know where the original is! As far as I can tell, the file type of the original file was changed to be an alias. I know that if you accidentally change the file extension of a file, you can change it back and the file will behave as it originally did, but for an alias changing the file extension doesn't do anything. Also, under "Get Info", there is no "Open with" option, so I can't tell it to open with DiskImageMounter.app.

Is there any other way to force OS X to think of the file as a .dmg, or to force the file to open with DiskImageMounter.app?

I am running OS X version 10.8.2, if that helps.

Thank you for any input you can provide.