Epplus : how to display double quaotes in string concatenation formula

I want to display something in col 1 as following:

  Unique Identifier       Display_Reg    Year   Month   Region  LO Count    
        2016_Apr_ENY    ENY     2016    Apr Albany     10   
        2016_Mar_ENY    ENY     2016    Mar Albany     11

I am getting values in Cells of col 1 as:

 worksheet_LO.Cells[Rowcount, 1].Formula = "=CONCATENATE(C" + Rowcount + "," +"D" + Rowcount + "," + "B" + Rowcount + ")";
 worksheet_LO.Cells[Rowcount, 1].Calculate();

Above gives me result as 2016AprEny. How to Display Underscore among them.

Solution

The Goal is to end up with this formula in the cell:

=CONCATENATE(C1,"_",D1,"_",B1)

To achieve this you need to add the ,"_", string into your concatenation where you had just the ,. in order to do this we need to be careful to escape the " character by adding another in front.

This should do it:

worksheet_LO.Cells[Rowcount, 1].Formula = "=CONCATENATE(C" + Rowcount +@",""_"","+"D" + Rowcount + @",""_""," + "B" + Rowcount + ")";
worksheet_LO.Cells[Rowcount, 1].Calculate();