Well, I accept your objection against starting a new thread for a same topic. That's why you have 11 nice glowing dots under your name that makes you excellent, while I've only one, a newbie! But ok, I expect within a year I'll have such glowing dots of experience, let me figure out the analog electronics in detail!
No, I did care it. Actually, I learned a lot like kelvin measurements and why a constant current source is preferred than a constant voltage when a very low resistance is measured from the previous thread. I closely followed ron's circuit (which he posted after a fun filled entertaining work day!!), and that helped me a lot to understand the CC mechanism.
Later, in a few days, I left my course's classical mechanics, and started figuring out the opamp basics from a book called Electronic Devices and Circuits, some web tutorials, some application notes and ron's and eric's circuit.
I've come up with the following circuit. I know the opamps need an upgrade to a better one. I've used 100mΩ sense resistor, so less voltage drop. The voltage source V2 for current adjustment should be replaced with some circuity+digipot. So, any suggestion about this CC?