Fetch number from Alpha numeric string

CREATE FUNCTION dbo.udf_GetNumeric

(@strAlphaNumeric VARCHAR(256))

RETURNS VARCHAR(256)

AS

BEGIN

DECLARE @intAlpha INT

SET @intAlpha = PATINDEX('%[^0-9]%', @strAlphaNumeric)

BEGIN

WHILE @intAlpha > 0

BEGIN

SET @strAlphaNumeric = STUFF(@strAlphaNumeric, @intAlpha, 1, '' )

SET @intAlpha = PATINDEX('%[^0-9]%', @strAlphaNumeric )

END

END

RETURN ISNULL(@strAlphaNumeric,0)

END

GO

SELECT dbo.udf_GetNumeric('aVI12345NASH67890') AS 'aVI12345NASH67890';