DataGridView CellBorderStyle's Bottom Line - Remove?

Hi,
Iam using VC++2010.

I have a DataGridView called MyDataGrid1, and based on a field value I need to hide the bottom line for certain rows.

// Declared in Top
Private: static DataTable^ MyStudentsDtb = gcnew DataTable();

Form_load()

MyStudentsDtb->Columns->Add("sl_no", System::Type::GetType("System.String"));
MyStudentsDtb->Columns->Add("standard",System::Type::GetType("System.String"));
MyStudentsDtb->Columns->Add("student_section", System::Type::GetType("System.String"));
MyStudentsDtb->Columns->Add("no_of_student", System::Type::GetType("System.Int32"));

MyDataGrid1->DataSource = MyStudentsDtb;


My Requirement...
01. Once the user enters '20' in no_of_student columns, then I want to remove the CellBorder Lines on that row and further 19 rows below to that CurrentRow, Is this possible?

02. Also when I check the table other than Form_load its not showing its rows, simply it says, zero rows... To access that datatable with its data, to other events & handles I don't know to do.....
Any Ideas will be welcome...


Thanks For The Help..