Formula for a Variable value every nth month

1.xlsx

Hi

The following file shows a payment plan that shows the next payments after a certain number of months, is there a way to do that?

you can see that the first payment is a 30$% upfront payment, then after six months the second payment of 10% of the original value is due... how can I translate that to be an automatic calculation?

I tried: =IF(MOD(COLUMN / and also : =IF(MOD(MONTH ... but that will only work for FIXED cell - every regular time interval, a fixed payment every 6 months but will not be dynamic...

I have colored the cells that should have value, when you look to the attach file it will be easily understood

Thank you in advanceUntitled.png

Please replace the question marks in the coloured cells with your expected results (manually calculated) so that we know what we're aiming for.

Maybe this copied across and down:

=IFNA(IF(INDEX($D31:$AC31,,MATCH(EDATE(D$3,-6*ROWS(D$32:D32)),$D$3:$AC$3,0))>0,INDEX($D$22:$AC$22,,MATCH(EDATE(D$3,-6*ROWS(D$32:D32)),$D$3:$AC$3,0))*$B12,""),"")

It's a bit of a work in progress - have a look and let us know what is and isn't right about it. Be SPECIFIC (i.e. not just "x is wrong" - tell us what x should be instead).