Match dates to amount vba

[fkaaelaursen]

Hi,

I'm quite new to excel modelling, and I've been asked to create a model of controlling an employee warrant program.

I'm in trouble of solving the following situation:

An employee are exercising:
4/6 - 20 warrants
6/6 - 20 warrants
18/6 - 7 warrants

When the warrants are exercised they are converted to shares that will be sold by the broker.

The broker sells:
4/6 - 16 shares
5/6 - 4 shares
6/6 - 20 shares
18/6 - 7 shares

Now that I know all the sell transactions, I need to allocate the correct exercise date to the sell trades for tax purposes, for instance:

4/6 - 16 shares
4/6 - 4 shares
6/6 - 20 shares
18/6 - 7 shares

We are using a FIFO principle, first shares exercised are first shares sold.
How can I create a vba sub function to sum shares sold until first exercise amount is met e.g. 20 and then allocate the first exercise date to these trades? The code should then sum shares sold that are not already given an exercise date until second exercise amount is met e.g. 20 and so on.

I really hope you can help me guide me in the right direction as this is the last bit of the model that I need to complete.