If you want to avoid using the MaskEdit control tnen you can use a regular TextBox and restric the user to have only 2 (or whatever number) of decimal points there. Put this code on KeyPress event of that TextBox:
Code:
Private Sub Text1_KeyPress(KeyAscii As Integer)
    Select Case KeyAscii
        Case 8
        Case 46
            If InStr(Text1.Text, ".") Then KeyAscii = 0
        Case Else
            If Not IsNumeric(Chr(KeyAscii)) Then KeyAscii = 0
            If InStr(Text1.Text, ".") Then
                If Len(Mid(Text1.Text, InStr(Text1.Text, ".") + 1)) = 2 Then
                    KeyAscii = 0
                End If
            End If
    End Select
End Sub
This will allow only Numbers, Decimal Point and Backspace.