How to make function by c# to call stored proc from sql

Question

I work in visual studio 2015 c# and i need to call stored procedure from sql 2012

and make function by c# to call stored procedure and retrieve one value string

in case name = @name 

 

ALTER PROCEDURE [dbo].[ATC_Code_ByGeneric_H]
    @Lvl_Name nvarchar(500)
AS
    SELECT     Tbl_Lvl1.Code + Tbl_Lvl2.Code + Tbl_Lvl3.Code + Tbl_Lvl4.Code + Tbl_Lvl5.Code AS ATC_Code
    FROM         Tbl_Lvl1
                 INNER JOIN
                 Tbl_Lvl2
                 ON Tbl_Lvl1.S_ID = Tbl_Lvl2.UpLvl_ID
                 INNER JOIN
                 Tbl_Lvl3
                 ON Tbl_Lvl2.S_ID = Tbl_Lvl3.UpLvl_ID
                 INNER JOIN
                 Tbl_Lvl4
                 ON Tbl_Lvl3.S_ID = Tbl_Lvl4.UpLvl_ID
                 INNER JOIN
                 Tbl_Lvl5
                 ON Tbl_Lvl4.S_ID = Tbl_Lvl5.UpLvl_ID
    WHERE     (Tbl_Lvl5.Lvl_Name = @Lvl_Name) and Tbl_Lvl5.human=1
    RETURN

 Actually i need to retrieve ATC_Code in case of Lv1_Name = @Lv1_Name

How to create function return string by c# to call stored procedure ?