Firstly, make a backup of your company file. Next, process your pay in the normal fashion, but on the Process Pays screen, click on the Advance tab and select to pay this one employee. Next on the Pay Dates tab, adjust the two dates - Pay end Date and Date Paid - to the correct dates.
Now continue on to complete the pay.
If this does not turn out correctly you can restore your backup and try again.
On your next pay run, check the Pay Dates tab and make sure they are showing the correct dates for that pay run.