T SQL : Convert string value to 2 decimal value

USE [MyTestDb]

GO

DROP FUNCTION [dbo].[udf_Global_PadTwoDecimalDigitString]

GO

SET ANSI_NULLS ON

GO

SET QUOTED_IDENTIFIER ON

GO

CREATE FUNCTION [dbo].[udf_Global_PadTwoDecimalDigitString](@StringDecimalValue varchar(25))

RETURNS varchar(25)

AS

BEGIN

DECLARE 

@Value varchar(25)

,@ValueAsFloat decimal(20, 3)

,@ValueAsFloatBackToVarchar varchar(25)

,@ValueAsVarcharWith2Decimal varchar(25)

SET @Value = @StringDecimalValue

-- Ensure that it has decimal values, if not, forced to add .00

SET @Value  = @Value + (CASE WHEN CHARINDEX('.', @Value) = 0 THEN '.00' ELSE SPACE(0) END)

-- Secret sauce:

SET @ValueAsFloat = CAST(@Value AS decimal(20, 3)) + .001

SET @ValueAsFloatBackToVarchar = CAST(@ValueAsFloat AS decimal(20, 3))

SET @ValueAsVarcharWith2Decimal = SUBSTRING(@ValueAsFloatBackToVarchar, 1, CHARINDEX('.', @ValueAsFloatBackToVarchar) + 2)

    RETURN @ValueAsVarcharWith2Decimal

END

GO