Excel VBA code for serial port to communicate with Modbus RT

Looking for VBA excel Code to read data from slave equipments via the serial port of a PC. The PC/software is the master and the equipments will be slaves. The communication protocol is MODBUS. The equipments generally have RS485 RTU. So, a B & B Electronics connector is used to convert from RS232 to RS485. The data from different registers should be requested on a regular basis and stored in the excel sheet indefinately. The equipments should be configured for their addresses, automatically. Please contact for further details.