Как перевести число из одной системы счисления в другую.

Dim a, b, c, d, n, h, m, k, s, x As Integer
 
Private Sub CommandButton1_Click()
s = Len(TextBox1.Text)
a = Val(TextBox1.Text)
b = Val(TextBox2.Text)
c = Val(TextBox3.Text)
d = Val(TextBox4.Text)
TextBox5.Text = s
k = 0
h = a
m = ""
 
 
If b = 10 Then
While h > 0
n = h Mod c
If n > 10 Then
If n = 10 Then n = "A"
If n = 11 Then n = "B"
If n = 12 Then n = "C"
If n = 13 Then n = "D"
If n = 14 Then n = "E"
If n = 15 Then n = "F"
End If
m = n & m
h = Int(h / c)
k = k + 1
Wend
TextBox4.Text = m
End If
 
If c = 10 Then
n = a
m = 0
While s > 0
h = n Mod 10
m = m + h * (b ^ k)
k = k + 1
s = s - 1
n = Int(n / 10)
Wend
TextBox4.Text = m
End If
 
If b <> 10 Then
If c <> 10 Then
n = a
g = s
m = 0
While g > 0
h = n Mod 10
m = m + h * (b ^ k)
k = k + 1
g = g - 1
n = Int(n / 10)
Wend
TextBox7.Text = m
h = m
x = Str(m)
g = Len(x)
TextBox6.Text = g
k = 0
m = ""
While h > 0
n = h Mod c
If n > 10 Then
If n = 10 Then n = "A"
If n = 11 Then n = "B"
If n = 12 Then n = "C"
If n = 13 Then n = "D"
If n = 14 Then n = "E"
If n = 15 Then n = "F"
End If
m = n & m
h = Int(h / c)
k = k + 1
Wend
TextBox4.Text = m
End If
End If
 
End Sub

Function LngToStr(ByVal Value As Long, Baza As Byte) As String 
 Dim M As Byte 
 Do 
   M = Value Mod Baza + 48 
   If M > 57 Then M = M + 7 
   Value = Value \ Baza 
   LngToStr = Chr$(M) & LngToStr 
 Loop While Value > 0 
 End Function 
 
 Function StrToLng(Value As String, Baza As Byte) As Long 
 Dim M As Byte, I As Byte 
 For I = 1 To Len(Value) 
   M = Asc(Mid$(Value, I, 1)) - 48 
   If M > 9 Then M = M - 7 
   StrToLng = StrToLng * Baza + M 
 Next I 
 End Function 
 
Private Sub CommandButton1_Click()
  TextBox4=LngToStr(StrToLng(TextBox1.text, val(TextBox2.Text)), val(TextBox3.Text))
End Sub