Sure:

at ufnHEXtoSID after this:

set @res = substring(@hexNumbBIN, @step,1)

select @AuxChar = dbo.BINtoASCIItoHEX(ascii(@res))

set @auxchar = isnull(@auxchar, '')

add this:

if len(@auxchar)= 1

set @auxchar = '0' + @auxchar

Regards