what you have described is something that IPAM normally does. So it scans all IP addresses not just used/static ones. You just need to have them defined within IPAM ( you need to see each IP address that you want to poll as part of subnet detail page).
IPAM will automatically detect if IP is responding and it changes the state from available to used + it retrieves SNMP details if available. If this is not working for you I would contact support and they should be able to help you with your issue.