Hi.,
Hope im correct jus try this and some may come out with an optimized Query.
DECLARE @NumStr varchar(1000)
declare @num int
SET @NumStr = 'T5e3st003';
set @num=(select PATINDEX('%[A-Z]%[A-Z]%[A-Z]%',reverse(@NumStr)))
BEGIN
WHILE PATINDEX('%[^0-9]%',@NumStr)> 0
SET @NumStr = REPLACE(@NumStr,SUBSTRING(@NumStr,PATINDEX('%[^0-9]%',@NumStr),1),'')
END
select right(@NumStr,@num-1)