without trying myself, I would suggest using recno() function instead, because the help says:
Returns an integer for the number of the currently read row of the input table. The first record is number 1.
Returns an integer for the position of the current row in the resulting QlikView input table. In contrast to RecNo( ), which counts the records in the raw data table, the RowNo( ) function does not count records that are excluded by where clauses and is not reset when a raw data table is concatenated to another. The first row is number 1.