Creating a new «spread» every time a dummy variable changes

Hi

I’m trying to create a new spread (In price) for each time «type» changes between 0 and 1. An example of this is C2 being subtracted by C3 (creating a value), and the next value being created by subtracting C3 with C4.

There are instances where «type» 1 occurs several times in a row. Then i would like a spread to be created by each «1» and the latest «0».
In the bigger dataset there are instances with several «0»’s in a row.

I have manually calculated how I would like the spreads to be calculated in a sample workbook (Manual calculations of desired results).

Hope i made myself clear! Any help would be appreciated

We are collaborating on this issue. We felt that that we didn't made ourselves clear with the first post, therefore we created a new thread where we tried to formulate our problem better.