RS-232 Arduino Filtering

I need an Arduino program to act as a serial-232 to serial-232 translator for a home automation security panel. The panel sends output via RS-232, and I require the Arduino to modify this data before passing it to a second RS-232 output.

Key Requirements:
- Read RS-232 data from the security panel.
- Modify the data based on specified criteria.
- Output the modified data to a second RS-232 port.

Ideal Skills and Experience:
- Proficiency in Arduino programming.
- Experience with RS-232 communication.
- Knowledge of data modification and filtering techniques.

Please provide relevant experience in your bids.