In my experience, USB based network adapters are nigh on impossible to get working under WinPE, as they seen to need full operating system support to work properly. However, I cannot say for certain that this applies to all modern hardware so my first suggestion would be to contact Panasonic tech support and ask them whether they have a solution to getting their NIC running under WinPE.
In general, WinPE needs a driver file set which consists of AT LEAST one .SYS file, one .CAT file and one .INF file, and sometimes one or more DLL files may be required. If you open the INF file in a text editor, there is usually a list of the required files somewhere in the INF. The DRVLOAD method can be used to quickly test a driver file set by loading the INF from the command line and seeing whether a success or failure message is returned.
However, if you cannot get the NIC mounted, the alternative is to use either a USB hard disk or a USB flash drive that boots WinPE and can thereafter directly run Ghost from the external HD or flash drive and load the image on the stick onto the Panasonic. Probably going to be a lot quicker than over the LAN anyway.