I don't know mitsubishi at all, but i would just let the counter count, and multiply its accumulator value by 2.55, depositing the result in D1
Count=0 D1=0
Count=1 D1=2.55
Count=2 D1=5.1
etc.
D1 would need to be a floating point register, or you will get
Count=0 D1=0
Count=1 D1=3
Count=2 D1=5
Count=3 D1=8
Count=4 D1=10