Lease with residual

[BRISBANEBOB]

I am trying to construct a table where a loan (say $500,000) is 50% amortised over a given period (say 5 years) at a fixed interest rate. I can't work out the formula which will allow it to calculate interest on the full $500k in the monthly repayments but only make capital repayments on $250k

I am trying to use PMT. Is that suitable?

Thanks for any advice.