I might be able to help, depending on how the table is being created. There are some non production rtf options that mgiht help, if the table is created with a "footer" section. that will depend on the proc being used.
If the table row is part of the body of the table, it gets very difficult.
I am using proc report to create the tables.
The table row is part of the body of the table.
I found some code from a SAS paper that uses the call define in a compute block and RTF tags to get the desired effect for the line under the second to last row of the table. Of course, it would be great to find a more efficient option that is easier to code. Perhaps in future SAS versions?