Unfortunately, my CMOD setup is not accessible or I would have tried loading a test data.
But as far as I can recall, whenever you set up CMOD to load a custom data, it prompts you to specify the file extension for this custom data (.txt, .doc, etc). CMOD uses this extension to search for a suitable viewer in your system (MSWORD for .doc files, notepad for .txt file, etc).
In your case since you cannot read binary data anyway you could mention the extension as '.txt'.
Have you already specified any extension??
Let me see if I can access my CMOD environment.
I will get back with any updates.
Cheers
Pankaj.