Good morning Vivian,
I vaguely remember the other thread. As I recall, one option was to manually record results, but you wanted a more automated system. At the time, we did not know how the sensor worked. With the new information here, we can say that digital information is supplied to the MCU. That is, an A/D converter is not needed.
Rather than try to figure out what is gong on inside the COB, I think it would be easier to start anew. You could use a 16-pin or 18-pin PIC to take the data from the sensor's 12 wires and calculate the slider's (moving contact) position. Then using geometry or a calculated table, determine the distance between the pincer tips. Finally, transmit the data to your data logger and to a serial LCD display. It is probably easier to buy a new display, rather than hack the one on the device you already have. You would need to study the current display more to decide whether it can be hacked.
John