Adding the lines to the row format does not make them immediately available to add to the merge document in word.

The reason for this is that the merge document is not looking directly at FIMS itself.  The merge document is looking at the export that comes out of FIMS.

In order to make the merge field available you will need to run the export from FIMS,   Once the export is complete, make sure that the merge template is connected to the export and then you should be able be to add the new merge field to you document.