Solution:

It's recommended to use the PCL-818HG or PCI-1710HG and a accurate resistor to achieve your goal. Mainly because these two cards have the high gain feature, so they can be used for measure the Thermocouple signal. Besides, you can parallel a accurate resistor between those two differential input terminals to get a 0-20mA input range. For example, one 50 ohm 0.1% resistor PCI-1710HG or PCL-818HG at 0-1V Unipolar input range Then 50 ohm * 20 mA = 1 Voltage.