tried case

SELECT NAME ,

CASE WHEN id = 4

AND id NOT IN ( 1, 2, 3 ) THEN 'C'

WHEN id <> 4

AND id IN ( 1, 2, 3 ) THEN 'R'

WHEN id IN ( 1, 2, 3, 4 ) THEN 'RC'

ELSE CONVERT (VARCHAR(10), id)

END

FROM tblTestId