How to add font size from the datagrivew column

Please welcome me as am a new member.

I have a datagridview with 7 columns on it. all this are xml file which get loaded to the datagridview. my columns are are follow

Department , Employment , Permanent , contract , Fontsize.

1. I have a xml file called employees which get loaded to my datagridview


2. The user will capture the data from the column cells


3. On Fontsize column. i want the user to enter only two numbers or one for incresing the font size of the current row.


4. if the user enters fontsize of 10, the current cell rows will change the font size(which mean department,employment,permanent and contract will change their font size).


5. the change will only happen on the current cell selected. e.g if you change for columnIndex 1. only column index row will change fontsize.


6. I have do the validations for allowing only numbers, but i want it to take two numbers only.

How can i change my fontsize of column index based on the number entered. I know of font dialog but thats not how i want it to be, i have use it for other client project.

I got this example but it is not how i want it as it got style. i only need fontsize

WinForms DataGridView font size

my validations

    private void Gridview_Output_CellEndEdit_1(object sender, DataGridViewCellEventArgs e)
    {
        try
        {
            #region this one validate the font number/ restrctions
            int RowIndex = e.RowIndex;
            int columnIndex = e.ColumnIndex;
            if (e.ColumnIndex == 2)
            {
                bool validation = true;
                if (Gridview_.Rows[RowIndex].Cells[columnIndex].Value != null && Gridview_.Rows[RowIndex].Cells[columnIndex].Value.ToString().Trim() != "")
                {
                    string DataToValidate = Gridview_.Rows[RowIndex].Cells[columnIndex].Value.ToString();
                    foreach (char c in DataToValidate)
                    {
                        if (!char.IsDigit(c))
                        {
                            validation = false;
                            break;
                        }
                    }
                    if (validation == false)
                    {
                        MessageBox.Show("Font must be numbers only", "Error Message", MessageBoxButtons.OKCancel,MessageBoxIcon.Warning);
                        Gridview_.Rows[RowIndex].Cells[columnIndex].Value = "";
                    }
                }
            }    

loading the file

               XmlDocument doc = new XmlDocument();
                doc.Load(Employee);  

my gridview column indexes

   Gridview_.Rows[i].Cells[1].Value.ToString(); // for Department
   Gridview_.Rows[i].Cells[2].Value.ToString(); // for Employment
   Gridview_.Rows[i].Cells[3].Value.ToString(); //for Permanent
   Gridview_.Rows[i].Cells[4].Value.ToString(); //for Contract
   Gridview_.Rows[i].Cells[5].Value.ToString(); //for Fontsize    

Thanks for your help and i hope my question is constructive enough