Código PHP:
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim reemplazo As String
Dim resta As Double
Dim div As Double
Dim resultado As Double
reemplazo = Replace(TextBox1.Text, ":", ".")
div = Fix(reemplazo)
resta = reemplazo - div
resultado = resta * 1.66
TextBox2.Text = resultado + div
End Sub
End Class
Crea en el formulario de diseño dos textbox y un boton