If you need access to a database that's source address lookup protected then you can either:
1 varify if they can do it based upon reverse DNS instead and use dynamic DNS to keep your IP associated with a DNS record. (ISP should be able to do dynamic RDNS for you)
2 you can ask your isp if you can buy a static IP for a small fee per month.
3 Use some external proxy so that to the hosting company access routers your source IP appears to be the same despite your actual IP changing.