I can't test this right now but I think this might work...
Step 1 - You could use the "Locale Execute Plugin" to run a command
like this: "ls /sdcard/somedirectory > /sdcard/filelist". That will
put a file list in the file named "filelist" on the sdcard..
then use Tasker to ...
2 Read Line > filelist to %MYFILE
3 Copy File %MYFILE to wherever if %MYFILE doesn't match EOF
4 GoTo 2 if %MYFILE doesn't match EOF