Convert to base n functions.

Hi all,
It's been a while since I last posted anything in the code bank, but today I made to useful functions that I thought I would share with you guys.
The functions convert base 10 integers to any base you like, with any alphabet you like. The second function can also convert base n numbers of any alphabet back to a base 10 integer. In the second function it would probably be more efficient to use some type of dictionary or lookup instead of index of.

vb.net Code:

Function ConvertToBase(ByVal Base As Integer, ByVal alphabet As String, ByVal number As Integer) As String
        Dim modv As Integer = number
        Dim div As Integer = number
        Dim st As New System.Text.StringBuilder()
        While div <> 0
            modv = div Mod Base
            div = div \ Base
            st.Append(alphabet(modv))
        End While
        Dim rev As Char() = st.ToString.ToCharArray
        Array.Reverse(rev)
        Return rev
    End Function
 
    Function ConvertFromBase(ByVal Base As Integer, ByVal alphabet As String, ByVal number As String) As Integer
        Dim acc As Integer
        Dim rev As Char() = number
        Array.Reverse(rev)
        For i = 0 To number.Length - 1
            acc += (alphabet.IndexOf(rev(i))) * (Base ^ i)
        Next
        Return acc
    End Function

And here is an example usage

vb.net Code:

RichTextBox1.AppendText(ConvertToBase(16, "0123456789ABCDEF", 34623) & vbNewLine)
        RichTextBox1.AppendText(CStr(ConvertFromBase(16, "0123456789ABCDEF", "873F")))

Output:

Code:

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873F
34623

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You could probably create a third function that can convert base n for any arbitrary alphabet to another base n with an arbitrary alphabet. I can think of many interesting things these functions could be used for.