@Joe90 I was specifically responding to the PAYE exclusion order query.
@Dublin 66 is absolutely correct in what he is saying. I got an exclusion order last year and it was dated the application date (I did fax it, maybe that made a difference).
If the company is paying the foreign employee from Ireland, Irish payroll taxes apply. Therefore you need a PAYE exclusion order.
It's only outside scope of Irish payroll taxes if paid outside of Ireland. The company may need to register in that company and return local payroll taxes.