Sys Traceability : Unable to create a covered link between a requirement object and a Word document requirement object detected with a pattern.

Hello, 

I've succeeded in building a word pattern that can properly interpret my Word document and highlight the requirements.
The problem is that I can't create any coverage links between these Word requirements and any other requirements in a requirements specification.

Is this possible? (I hope so.)
Can anyone help me figure out the procedure or conditions to respect?