I believe this will do it for you...

CREATE FUNCTION dbo.RemoveNonDisplayChars

/********************************************************************

Purpose:

Remove the non-displayable control characters from CHAR(0) to

CHAR(31) and the DELETE character CHAR(127).

Revision History:

Rev 00 - Jeff Moden - 06 Feb 2010 - Initial Release and Unit Test

********************************************************************/

--===== Declare the I/O parameters

(@pString VARCHAR(8000))

RETURNS VARCHAR(8000)

AS

BEGIN

--===== Declare Local variables

DECLARE @IncorrectCharLoc SMALLINT, --Position of bad character

@Pattern CHAR(37) --Bad characters to look for

SELECT @Pattern = '%['

+ CHAR(0)+CHAR(1)+CHAR(2)+CHAR(3)+CHAR(4)

+ CHAR(5)+CHAR(6)+CHAR(7)+CHAR(8)+CHAR(9)

+ CHAR(10)+CHAR(11)+CHAR(12)+CHAR(13)+CHAR(14)

+ CHAR(15)+CHAR(16)+CHAR(17)+CHAR(18)+CHAR(19)

+ CHAR(20)+CHAR(21)+CHAR(22)+CHAR(23)+CHAR(24)

+ CHAR(25)+CHAR(26)+CHAR(27)+CHAR(28)+CHAR(29)

+ CHAR(30)+CHAR(31)+CHAR(127)

+ ']%',

@IncorrectCharLoc = PATINDEX(@Pattern, @pString)

WHILE @IncorrectCharLoc > 0

SELECT @pString = STUFF(@pString, @IncorrectCharLoc, 1, ''),

@IncorrectCharLoc = PATINDEX(@Pattern, @pString)

RETURN @pString

END

GO