A Tally table (or in this case a cteTally) can come to the rescue.

Check the following code and ask for anything that you don't understand.

WITH E1(n) AS(

SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1

UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1

),

cteTally(n) AS(

SELECT TOP 50 ROW_NUMBER() OVER( ORDER BY ( SELECT NULL))

FROM E1, E1 b

)

SELECT cust, SUBSTRING(wptext, (80 * (n-1)) + 1, 80 ) AS wptext, n as seq

FROM TableA a

JOIN cteTally t ON t.n <= CEILING( LEN( a.wptext) / 80.0)

order by cust, n