I'm not sure exactly what you mean, but the best way to measure current is by using a "current viewing resistor", or CVR. A CVR is just a resistor with a decent wattage rating and a low value, such as your 0.1 ohm resistor.
When current passes through your resistor, it will create a small voltage. This voltage is related to the current by Ohm's law, V=IR, where the voltage is the current times the resistance value.
Therefore, if you have an idea of what your maximum current will be, take that times your resistance (0.1), and that will be the voltage you will see. This will allow you to set the max/min range.
However, you can set up your channel as VOLTAGE input. Read the voltage, divide it by 0.1, and you'll have the current.
Does that hel
p?
Mark