How can you format a persisted column as a padded integer string [SQL Server 2008]

Question

What formula would I use in a persisted column so that I can add the two columns below together, the first must be padded to 5 characters:

• ID (INT)
• RefNum (STRING)

I went for format(ID,"00000") & RefNum, but it doesn't work, any ideas please?

Answer 1

SELECT RIGHT('00000' + CAST(ID AS VARCHAR(5)), 5) + RefNum