More Information on Font Suitcases: http://en.wikipedia.org/wiki/TrueType#Suitcase
Fonts that are in a font suitcase are locked down from pretty much everything but specific programs on the Mac that use the Font Suitcase.
Even extremely popular web tools such as this one are not compatible with fonts in a font suitcase: http://www.freefontconverter.com/
If you'd like to use the fonts with MyOrderDesk you're going to need to extract the fonts from the suitcase.
Here are a few links to get you started if you're not familiar with extracting fonts
Again, fonts inside of a font suitcase do not have file extensions which means they cannot be uploaded into an Advanced ezMerge template. Those fonts must be extracted in order to upload them. This is not specific to MyOrderDesk. Many applications require fonts to be removed from the suitcase before using them.