Proyecto:
Option Explicit
Private Sub LaVolpeButton1_Click()
Enc Text1.Text, Text2.Text ' cifra el texto y pone los caracteres en el fichero de texto
End Sub
y la del modulo:
Option Explicit
Function Enc(Texto As String, Ruta As String)
Dim Codigo
Dim Actual
Dim i
For i = 1 To Len(Texto)
Actual = Hex(Asc(Mid(Texto, i, 1)) Xor 23)
Codigo = Codigo & Actual
Next
Open Ruta For Append As #1
Print #1, Codigo
Close #1
End Function

Option Explicit
Dim X0 As Integer
Dim X1 As Integer
Dim X As Single
Dim Y As Single
Dim c
Dim PosX As Integer
Dim PosY As Integer
Private Sub cmdDibujar_Click()
PosX = 0
PosY = Picture1.Height / 2
X0 = Val(lblX0)
X1 = Val(lblX1)
c = 1
If X0 = 0 Then X0 = 1
Picture1.DrawWidth = 2
For X = X0 To X1 Step c
Y = -Y * 4: Y = Y / Picture1.Width + PosY: PosX = X + (Picture1.Width / 2)
Picture1.PSet (1 + PosX, 1 + Y)
Next X
End Sub

Private Sub Form_Activate()
Picture1.DrawWidth = 1
Picture1.Line (0, Picture1.Height / 2)-(Picture1.Width, Picture1.Height / 2)
Picture1.Line (Picture1.Width / 2, 0)-(Picture1.Width / 2, Picture1.Height)
End Sub

Private Sub HSX1_Change()
lblX1 = HSX1.Value
End Sub

Private Sub HSX0_Change()
lblX0 = HSX0.Value
End Sub