Unfortunately, you can't. As you can see on the official WinWCP user guide, the program can import only .abf, .dat, .cfs, .sca, .ibw and .asc files. In order to import the WindEDR data to WinWCP, you will need to export it to one of these formats. You can do this following the instructions from WinEDR user guide. The necessary steps are at page 173. Before beginning the transferring process, make sure that you have the latest versions of the software.