There might be a program around, but personally, I wouldn't trust any with something so simple. If your old setup OS is the same as the new, it'll be rather painless. It -can- be done without going into regedit, but again, you probably should. Like I could give you my exported registry file, all you'd have to do is double click it and if your settings are the same (same POL install directory) it should be good to go.
To do it yourself, go to HKEY_Local_Machine\SOFTWARE\PlayOnlineUS\ and go to File > Export, and save it somewhere. It might be in a different location if you're under vista. Then copy the POL folder onto the new harddrive under the same tree directory, most likely c:\program files\playonline.
Create a text document in notepad with this code inside:
Code:
regsvr32 /s "FINAL FANTASY XI\FFXi.dll"
regsvr32 /s "FINAL FANTASY XI\FFXiMain.dll"
regsvr32 /s "FINAL FANTASY XI\FFXiResource.dll"
regsvr32 /s "FINAL FANTASY XI\FFXiVersions.dll"
regsvr32 /s "PlayOnlineViewer\polhook.dll"
regsvr32 /s "PlayOnlineViewer\unicows.dll"
regsvr32 /s "PlayOnlineViewer\patchfiles\PlayOnlineViewer\viewer\com\app.dll"
regsvr32 /s "PlayOnlineViewer\patchfiles\PlayOnlineViewer\viewer\com\polcore.dll"
regsvr32 /s "PlayOnlineViewer\polcfg\sysinfo.dll"
regsvr32 /s "PlayOnlineViewer\util\unicows.dll"
regsvr32 /s "PlayOnlineViewer\viewer\ax\MSVCR71.dll"
regsvr32 /s "PlayOnlineViewer\viewer\ax\polmvf.dll"
regsvr32 /s "PlayOnlineViewer\viewer\ax\polmvfINT.dll"
regsvr32 /s "PlayOnlineViewer\viewer\com\app.dll"
regsvr32 /s "PlayOnlineViewer\viewer\com\polcore.dll"
regsvr32 /s "PlayOnlineViewer\viewer\contents\PolContents.dll"
regsvr32 /s "PlayOnlineViewer\viewer\contents\polcontentsINT.dll"
regsvr32 /s "TetraMaster\TM.dll"
and save it as "something.bat" inside of the POL folder. Run this .bat file and the registry file you exported and everything should be installed and ready now, pending a file check.