sum of integer values in a lable retrive from database having formate ##,###.00

hi... all

plz help me for this regard...

I have 3 Label and want to sum of two values into third label with follow this formate.tostring("##,###.00;(## ,###.00);-")

Explanation ...... example ..

I featch the data from data base into 2 label. And want to add this value in third label

code...

.......

while (reader.Read())
            {

                 lbllab03.Text = Convert.ToDecimal(reader["LAB03"]).ToString("##,###.00;(##,###.00);-").Trim();
                lblmsc03.Text = Convert.ToDecimal(reader["MSC03"]).ToString("##,###.00;(##,###.00);-").Trim();
            }

Through this i can display the data in 2 lable like this..

1,300.00

200.00

i want to display 1,500.00 into 3rd label

i try this code for sum ...

lbltot03.Text = (Convert.ToInt32(lbllab03.Text.ToString("##,##,###.00;(##,##,###.00);-")) + Convert.ToInt32(lblmsc03.Text.ToString("##,##,###.00;(##,##,###.00);-"))).ToString("##,##,###.00;(##,##,###.00);-");

or try this also

lbltot03.Text = (Convert.ToDecimal(lbllab03.Text.ToString("##,##,###.00;(##,##,###.00);-")) + Convert.ToDecimal(lblmsc03.Text.ToString("##,##,###.00;(##,##,###.00);-"))).ToString("##,##,###.00;(##,##,###.00);-");

plz help me.......................