value

Returns value if value is exists. If the value does not exist, this method returns nil.

tobj = WIN32OLE_TYPE.new('Microsoft Excel 9.0 Object Library', 'XlSheetType')
variables = tobj.variables
variables.each do |variable|
  puts "#{variable.name} #{variable.value}"
end

The result of above script is following:
  xlChart = -4109
  xlDialogSheet = -4116
  xlExcel4IntlMacroSheet = 4
  xlExcel4MacroSheet = 3
  xlWorksheet = -4167