add item to datagridcombobox

i have a datagridview and i have a column combox.( first column)

i want to add item to combox of datagrid.

but i cant get name of it. please tell me.

try this :

Code:

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        Dim dgvcolum As DataGridViewComboBoxColumn
        dgvcolum = DataGridViewX1.Columns(0)
        dgvcolum.Items.Add("43634")
        dgvcolum.Items.Add("43634")
        dgvcolum.Items.Add("43634")
        dgvcolum.Items.Add("43634")

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