I too tried doing that, but for the life of me I couldn't figure out what is the device's address. That should be the basic thing that will be used to address the chip. Also I found three different programs in arduino library but couldnt find the device address in either of them.
I am following this approach, can you please check it to be right?
1. Initialise the I2C
2. I2C Start
3. I2C Stop (To start the chip, SDA should go from high to low as per the datasheet)
4. I2C Start
5. Send 0x48 on the I2C bus to address the chip
6. Send 0x67 on the I2C bus to address the left most digit
7. Send the data on the I2C bus
8. I2C Stop
9. I2C Start (To stop the chip, SDA should go from low to high as per the datasheet)
I am also sending you the links to the arduino based libraries I found for the chip.