How to get numerical static IP ?

Hello,
My problem is that i have a PACS behind my fiber connection (dynamic IP)
Everything works perfect at this time.
Our O-ARM (like a CT scan) in our office can send pictures to a PACS server but can only accept numerical IP and not DDNS like xxx.no-ip.xx ( nothing can be done on this side...)

I can not get a static IP with my internet provider.
So i need to find a service like no ip which gives me a static numerical ip instead of a classic address ?

Any idea welcome!!!!