there is no build in functionality but you may try following workaround:
1) Install IPAM and Toolset on the same machine.
2) Open the IP Address Management in Toolset and add a subnet
3) copy the .IPDB file from Toolset ( in 2008 it will be available in C:\Program data\solarwinds) and place it in IPAM folder. ( C:\Program Files\Solarwinds\Orion\IPAM)
4) Open the Command Prompt.
5) Go to: C:\Program Files\Solarwinds\Orion\IPAM> SolarWinds.IPAM.init.exe -import Overwrite -file "IPDB file name" and click enter
6) Restart Solarwinds services
you should get IPAT data into IPAM.
let us know if that works for you.