;WITH CTE AS
(
 SELECT ID,[Desc],
        LEFT(PARSENAME(REPLACE([Desc],' ', '.'), 3),1) AS String1,
	LEFT(PARSENAME(REPLACE([Desc],' ', '.'), 2),1) AS String2,
	LEFT(PARSENAME(REPLACE([Desc],' ', '.'), 1),3) AS String3,
	ROW_NUMBER()OVER(PARTITION BY LEFT(PARSENAME(REPLACE([Desc],' ', '.'), 1),3) ORDER BY ID) AS RNum1 
 FROM @tmpV
)
SELECT ID,[Desc],CONCAT(String1,String2,String3) AS DescID
FROM CTE
WHERE RNum1 = 1
UNION
SELECT ID,[Desc],
       CONCAT(String1,String2,CASE WHEN ROW_NUMBER()OVER(PARTITION BY LEFT(String3,2) ORDER BY ID) BETWEEN 1 AND 10 
	                           THEN LEFT(String3,2)+ CAST(ROW_NUMBER()OVER(PARTITION BY LEFT(String3,2) ORDER BY ID)  AS VARCHAR(10))
				   WHEN ROW_NUMBER()OVER(PARTITION BY LEFT(String3,2) ORDER BY ID) BETWEEN 11 AND 100 
				   THEN LEFT(String3,1)+CAST(ROW_NUMBER()OVER(PARTITION BY LEFT(String3,2) ORDER BY ID)  AS VARCHAR(10)) END
             ) AS DescID
FROM CTE
WHERE RNum1 > 1