Cumulative order for promotion goods

Hi,

I would like to know the feature of Trade Management can support cumulative order for promotion goods.

Our business need to setup promotion buy item A 100 ea. will get B free 1 ea.

The order from the same customer can open order more than 1 order and system keep record the total quantity for all orders until quantity order reach to 100 ea. system will popup B item automatic to the last order that reach 100 ea.

For example.

1st order request and booked Item A 30 ea.

2nd order request and booked Item A 40 ea. and

3rd order request and booked Item A 50 ea. and at this order system will get Item B free 1 ea. If Trade Management support this scenario please advice the step to setup offer step by step.