I have written a spreadsheet which calculates the date on which a
loan/mortgage will finally be paid off. Can anyone tell me how to set it up
so that the regular (monthly) payment falls on the same day each month,
taking into account 28/29/30/31 day months?

At the moment I have a Loan Start Date entered in cell H14 and a First
Payment Date in H16. Cell B22 = H16, and column B then automatically fills
down to provide approximately 30 years of individual dates, including leap
years. What I now need to do is have some kind of formatting for the Payment
column (in my case, D), which says =IF(H16=the eighth of the month, or
whatever, then make this payment every month on the eighth). HELP!!!! I've
been trying for a week now to do this!

(None of the templates I have been able to find allow you to amortize a loan
on a daily basis - the best I have seen is on a bi-weekly basis, which
doesn't work for the kind of loan I have)