Remove datagridviewcomboboxcell from 1 specific cell in a datagridviewcomboboxcollumn

I have an datagridview as shown in image 1 the row at the bottom does have 2 comboboxcell as expected because I set that collumn to that type. But i want to change that comboboxcell to an textboxcell but the other cells in that collumn needs to stay a comboboxcell. In the rows underneath klant and project, there are values except for the last row. this row needs to show the total of al the rows

Image1

I hope someone can help me out i can't find anything on go开发者_开发技巧ogle and here on stackoverflow.

You can set individual cells of a datagridview:

DataGridViewCell newCell = new DataGridViewTextBoxCell();
// Set more properties here.
dataGridView1[row, column] = newCell;