cell.rb

class Cell
    def self.parse(sheet, name)
        if name =~ /([A-Za-z]+)([0-9]+)/
            raise(ArgumentError, "Exceeds the maximum number columns (256 columns): #{top_left_cell.inspect}") unless COLUMNS.index($1)
            
            new(sheet, COLUMNS.index($1), $2.to_i - 1)
        end
    end
    
    def initialize(sheet, c, r)
        @sheet, @c, @r = sheet, c, r
    end
    
    def offset(offset = {})
        Cell.new(sheet, c + offset[:c].to_i, r + offset[:r].to_i)
    end
    
    def name
        "#{COLUMNS[c]}#{r+1}"
    end
    
    def to_s
        name
    end
    
    def set(value)
        # переносим сюда код set_cell
    end
    
    def range(data)
        data.each_with_index do |row, dr|
            row.each_with_index do |value, dc|
                offset(r: dr, c: dc).set(value)
            end
        end
    end
end

# в ExcelHelpers
def cell(name)
    Cell.parse(current_sheet, name)
end

# Использование:
cell('A1').range [[1,2,3], [4,5,6]]
cell('A2').offset(r: 3).range ....