License budgetting: Budgetting with continous payments using IF, MOD and starting date

Hello!
I would like to create a formula that evaluate the starting year of a contract, which inserts the value of the cost under the corresponding year in a budget. The catch is; i need to have intervals inserted also. For example: A contract from MS has to be paid every third year, the cost is 5000$ and the starting year is 2015. Therefore, in the budget, 5000$ should be inserted in the starting year 2015 then 2018, 2021 and 2024 etc.

For now my formula says;

=IF(STARTING YEAR=YEARINBUDGET;COST;"")

I simply can't figure out how to then copy, the amount inserted, if the argument is true, to the remaining years when the license has to be paid. I have tried using MOD, but this does not seem to work.

Picture to visualize what i imagine it will look like.

til forum.PNG



This should be build as a tool that can easily be updated continuously. :-)

Thanks in advance

//AV