Hi, I am not exactly sure how to say this, but what I want to do is to write a series of strings converted to their hex notation to a binary file. Here is what I have:

Code:
Dim hexNumbers As System.Text.StringBuilder = New System.Text.StringBuilder

    Private Sub add_byte(ByVal str As String)
        hexNumbers.Append(String.Format("{0:x}", Convert.ToChar(str)))
    End Sub

    Private Sub add_short(ByVal str As String)
        hexNumbers.Append(String.Format("{0:x}", Convert.ToInt16(str)))
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim fstream As New FileStream(Application.StartupPath & "\help.bin", FileMode.OpenOrCreate, FileAccess.ReadWrite)
        Dim bw As BinaryWriter = New BinaryWriter(fstream)

        add_byte(DataGridView1.Rows(0).Cells(0).Value)
        add_byte(DataGridView1.Rows(0).Cells(1).Value)
        add_byte(DataGridView1.Rows(0).Cells(2).Value)
        add_byte(DataGridView1.Rows(0).Cells(3).Value)
        add_byte(DataGridView1.Rows(0).Cells(4).Value)
        add_short(DataGridView1.Rows(0).Cells(5).Value)
        add_short(DataGridView1.Rows(0).Cells(6).Value)

        bw.Write(String.Format("{0:x}", hexNumbers)) '<-- doesn't change a thing

        bw.Close()

        MsgBox("Done")
    End Sub
Looking at a hex editor I see:

Code:
30 30 31 30        0 0 1 0
What I was going for was: 00 00 16 to be converted to 00 00 10 and have that value written to the binary file instead of the above 30 30 31 30.

So, what do I need to do to have the actual hex value written to the binary rather than it's ASCII equivalents?

Thanks