High Sensitivity Voltmeter approach? L7107

I've found a few sites explaining how to make a digital voltmeter using the L7107. Most are displaying the volts on 7 seg displays. I just want to measure volts and pass the reading to an Arduino.

I'm looking to measure milivolts in the range of 20mv-200mv. According to THIS , the L7107.

Anyone have any experience with this chip? Or another way to sense milivolts and give that value to the arduino?