From OVH's own website,
Add up to 16 geolocated IP addresses in France, Germany, Italy, Spain, the UK, Poland, Portugal, Ireland, the Czech Rep., the Netherlands, Finland, Lithuania and Belgium. Each IP comes with a setup fee of £1.69 ex. VAT . You can attach IPs from several countries to a single VPS, whatever the model.
So for a small fee you can get a IP address that appears to be in Poland. You then route traffic out using that address.
Note that a failover address is not necessarily a geolocated address. You should have ordered a geolocated address. Once you have that geolocated address (or address block) and you've assigned it to your VPS within the OVH control panel and added it to the VPS itself, you simply ensure that traffic leaving your system has the appropriate source IP address.
At the simplistic level, this could suffice:
# Add the IP address to your interface
ip addr add 1.2.3.4/32 dev eth0
# Ensure all traffic leaving the server is from the correct source
iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to 1.2.3.4.