Converts a number to an arbitrary radix (base), with configurable character set.

ConvertToBase.cs

public string ConvertToBase(uint value, char[] characterSet)
{
    var radix = (uint)characterSet.Length;
    var result = new List<char>();
    do
    {
        var remainder = value % radix;
        value = value / radix;
        result.Add(characterSet[remainder]);
    } while(value > 0);
    result.Reverse();
    return new string(result.ToArray());
}