Generating Large and more decimal Number in SQL

DECLARE @RandomNumber decimal(32,12)
DECLARE @RandomInteger bigint
DECLARE @MaxValue bigint
DECLARE @MinValue bigint

SET @MaxValue = 4000000000
SET @MinValue = 2

SELECT @RandomNumber = RAND()

SELECT @RandomInteger = ((@MaxValue + 1) - @MinValue) * @RandomNumber + @MinValue

--SELECT @RandomNumber as RandomNumber, @RandomInteger as RandomInteger

--select cast(@RandomInteger as varchar(200))+cast(@RandomNumber as varchar(200)) 

select [dbo].[FormatDecimalCharWithCommaRound](cast(@RandomInteger as varchar(200))+cast(@RandomNumber as varchar(200)) 
,4),cast(@RandomInteger as varchar(200))+cast(@RandomNumber as varchar(200)) 

select [dbo].[FormatDecimalCharWithCommaRound](.12345678,2)