Kual Button for Amazon apps?

Amazon has a number of E-ink Kindle compatible apps/games for free download on their website..

These get downloaded into /mnt/us/documents/..

I tried making a kual button for one of them : "My Checklist"..

The file is called : "My Checklist_B007L78Z7K.azw2"..

The string at the end(B007L78Z7K) seems to be an identifier which may be different for each user..

I got either Kual json file errors or "unable to start application" error messages..

Since inverted commas are already used for the path in the json file, i tried surrounding the file name again with them.. since there is an embedded space in the file name.. and then with apostrophes.. didn't work..

Any idea..?