ok. why would a LM3914 be used here? this is a VU meter circuit.
what you need is a counter.
if you want to have 100 running leds, 2 at a time then that means you only need to count to 50.
do you want to have them count from one direction, or go from one end to another, then reverse?
the simplest way you could do is to have them count in only one direction.
all you need for this is a 555, 2 4017 counters, and 5(or 10 if you want the leds to turn on one at a time) BC547 transistors and some descrete components.
the leds need to be wired intro a matrix.