PPMT function replacement

[Huskerpaulie]

I'm trying to use Excel on my Palm Centro to determine the breakdown between
interest and principal for monthly mortgage payments, but the built-in
software does not allow PPMT, IPMT, and IF statements to be used. I am
allowed to use functions such as FV, IRR, NPER, NPV, PMT, PV, and RATE.

What function/formula or combination of function/formulas could I use to
determine the same information that the PPMT function provides?

Thanks for your help.
-Paul

 

[Fred Smith]

For any period, principal reduction is:

Balance at start of period - Balance at end of period

Therefore PPMT for period n is:

FV(rate,n-1,pmt,mortgageamount) - FV(rate,n,pmt,mortgageamount)

Also, IPMT = PMT - PPMT