Getting the last two tokens in batch script for command

I have a file name with fullpath and want to get the filename and the parent directory of the file.How can I parse this in batchscript?

e.g
for /f "tokens=4,5 delims=\" %%a in ("F:\mydata\WebLogs\MyServerName001\u_ex100206.log")

in the above line token 4 is the servername and 5 is the filename.But this will not be always 4 and 5.So how can I get the last two tokens in a batch script?because in my scenario the filename will be the last token and the server name will be the token before that.