列名と値を指定し、その値が何行あるかを取得する

row_count = DATAGRID_MATCHCOUNT(dataGrid, column_name, operator, match_value);

/* 記述例 */
row_count = DATAGRID_MATCHCOUNT(dataGrid, 'is_complete_flg', '=', 'Y');

https://go.documentation.sas.com/doc/jp/edmcdc/v_056/edmdatagrids/n1ic8wboejbzb6n11vltlxtnz2is.htm