awk function for converting number to an alphabetic column

convertNumberToAlphabeticColumn.awk

function convertNumberToAlphabeticColumn(columnNumber) {
    dividend = int(columnNumber);
    alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    columnName = "";
    while (dividend > 0) 
    {
        mod = int( dividend ) % 26;
        columnName = substr( alphabet, mod, 1 )columnName;
        dividend = int( dividend - mod ) / 26 ;
    }
    return columnName;
}