Microsoft - Microsoft SQL Server - SQL - Format - Extract Integer from String

CREATE FUNCTION extractInteger(@string VARCHAR(2000))
RETURNS VARCHAR(2000)
    AS
    BEGIN
        DECLARE @COUNT INT
        DECLARE @intNumbers VARCHAR(1000)
        SET @COUNT = 0
        SET @intNumbers = ''
        WHILE @COUNT <= LEN(@string)
        BEGIN 
            IF SUBSTRING(@string, @COUNT, 1)>='0' AND SUBSTRING (@string, @COUNT, 1) <='9'
                BEGIN
                    SET @intNumbers = @intNumbers + SUBSTRING (@string, @COUNT, 1)
                END
            SET @COUNT = @COUNT + 1
        END
        RETURN @intNumbers
    END
    GO