How to convert a column number (e.g. 127) into an Excel column (e.g. AA)

How do you convert a numerical number to an Excel column name in C# without using automation getting the value directly from Excel.

Excel 2007 has a possible range of 1 to 16384, which is the number of columns that it supports. The resulting values should be in the form of excel column names, e.g. A, AA, AAA etc.

Here's how I do it:

private string GetExcelColumnName(int columnNumber)
{
    string columnName = "";

    while (columnNumber > 0)
    {
        int modulo = (columnNumber - 1) % 26;
        columnName = Convert.ToChar('A' + modulo) + columnName;
        columnNumber = (columnNumber - modulo) / 26;
    } 

    return columnName;
}

If anyone needs to do this in Excel without VBA, here is a way:

=SUBSTITUTE(ADDRESS(1;colNum;4);"1";"")

where colNum is the column number

And in VBA:

Function GetColumnName(colNum As Integer) As String
    Dim d As Integer
    Dim m As Integer
    Dim name As String
    d = colNum
    name = ""
    Do While (d > 0)
        m = (d - 1) Mod 26
        name = Chr(65 + m) + name
        d = Int((d - m) / 26)
    Loop
    GetColumnName = name
End Function