Need A Count Of '0', Even If Criteria Is Not Met In A Select SQL Statement

I have the following Select SQL Statement in which I get the count of the 'Code' column based upon a criteria and Group By clause:BEGIN

SELECT Code, COUNT(Code)as exprCount1a

FROM dbo.[Test]

WHERE Section = '1' and Item = 'a' GROUP BY Code ORDER BY Code

END

The results of the statement:

Code | exprCount1a 

1              2
2              4
4              1

I would like the following results:

Code | exprCount1a 

1              2
2              4

3              0
4              1

Note: Code ' 3 ' doesn't have any rows that meet the select count statement criteria but I still need to populate ' 0 ' in the results.

Thank you in advance