The only way we found to dynamically control this is to link the crystal report to an Access database 'numbers' table. The table contains some linking fields such as company and a qty field. The qty field would have to contain one row of 1, two rows of 2's, three rows of 3's and so on.
For example, you would join your UD field to qty field on the numbers table and it would find 25 records for the number 25. Place this qty field from the numbers table in the report and you get 25 pages of the same record. We typically hide it in the report footer. Your sequence numbering can be based on page number or a formula at that point.