Here is a generic algorithm to get the Excel column name according to it's position. By changing the @Base parameter, you can do this for any sequence according to same style as Excel.
DECLARE @Value BIGINT = 8839,
@Base TINYINT = 26
;WITH cteSequence(Position, Value, Chr)
AS (
SELECT CAST(LOG(@Value - @Value / @Base) / LOG(@Base) AS INT),
CAST(@Value - 1 AS BIGINT),
CAST(CHAR(65 +(@Value - 1) % @Base) AS VARCHAR(MAX))
UNION ALL
SELECT Position - 1,
Value / @Base - 1,
CHAR(65 +(Value / @Base - 1) % @Base) + Chr
FROM cteSequence
WHERE Position > 0
)
SELECT Chr
FROM cteSequence
WHERE Position = 0