Might look into the ROW_NUMBER() function.

CREATE TABLE #TmpTbl (ACTCODE NCHAR(6));

INSERT INTO #TmpTbl (ACTCODE) VALUES ('110001'), ('110003'), ('110009');

DECLARE @SEQUENCE NCHAR(6) = 220000;

SELECTACTCODE

, @SEQUENCE + ROW_NUMBER() OVER (ORDER BY ACTCODE)

FROM#TmpTbl;

DROP TABLE #TmpTbl;