Hi,
You need to set your "main currency" setting as euros. Then, in the System>Currencies menu, set your fictitious currency as displayed but not published.
And finally, in the zones where you want to use that currency, select that currency.
Then, configure your geolocation plugin.
That way, the geolocation plugin will set that currency when you arrive on the website if your geolocated zone is set to that currency. So you'll see the prices of the products in that currency. However, when you reach the checkout, the currency will be changed to euros automatically so that you can pay with PayPal (you'll see the before/after prices on the checkout along with a message saying that the currency has been changed).