How to creata a 2-column combination into a primary key in OLEDB with VB.NET

So I did an update in the "RPD" table and the database does not have a primary key then my solution must create a primary key in the "PNM" column but I can only update only 1 row so the solution is whether it can be by combining the "PNM" column with "NOD" then it becomes the primary key or is there another solution

Thanks

Table name : RPD These are the details with the product items

Table name : RPG This is the table master

Using cn As New OleDbConnection("provider=Microsoft.Jet.OLEDB.4.0; data source=" & Path & "; Extended Properties=dBase IV")
Using cmd As New OleDbCommand("ALTER TABLE RPD ADD CONSTRAINT idxMyTable PRIMARY KEY (PNM)", cn)
                cn.Open()
                cmd.ExecuteNonQuery()
End Using
End Using

As per this link : ALTER TABLE to add a composite primary key

  Using cn As New OleDbConnection("provider=Microsoft.Jet.OLEDB.4.0; data source=" & Path & "; Extended Properties=dBase IV")
        Using cmd As New OleDbCommand("ALTER TABLE RPD ADD CONSTRAINT idxMyTable PRIMARY KEY (PNM,NOD)", cn)

            cn.Open()
            cmd.ExecuteNonQuery()
        End Using
    End Using