'Translate a range col-snippet by the given number of columns'

@staticmethod
def translate_col(col_str, cdelta):

    if col_str.startswith('$'):
        return col_str
    else:
        try:
            return get_column_letter((column_index_from_string(col_str) + cdelta))
        except ValueError:
            raise TranslatorError('Formula    out    of    range')
