This may be tricky...

So I have a couple amortization tables (not shown) that I'm working on with one for 5 and one for 10 years. In this graph (that works off the amortization tables) I'm working with results from each table. It's complicated. The problem is that since the first amortization table (feeding results to columns A - E) ends after sixty months the cells in the amortization table that this table is trying to refer to in D10, D11 and D12 are, in fact empty. Hence the dreaded red triangles!! I wouldn't mind the red triangles there except that in I10, I11 and I12 which are supposed to sum their respective rows also get THE TRIANGLE! In columns D and E instead of red triangles we want zeroes. If not that then we want the I10,I11, I12 cells to treat them like zeroes. The reason for this is that currently the amortization table A is based on a five year term, but I do play around with the terms and it can go between 3 and 8 years depending.

Not that it matters, but if you notice that B columns numbers don't match M columns numbers it's only because the first amortization table is preceded by two years lease. Not that that matters.