Issue Running a Batch file and piping to a text Log file

I want to run a scheduled task that executes a .bat file. The .bat file works fine.  The problem I'm having is naming the .txt log file I create when running this .bat.

I hope this is clear - Here is what's happening:

From Command Prompt I run my batch file and pipe (>) to a .txt log file as follows:

                  batch.bat > logfile-%date:~4,2%-%date:~7,2%-%date:~10,4%_@_%time:~0,2%h%time:~3,2%m%time:~6,2%s.txt

This produces my logfile named appropriately with date and time as "logfile-03-10-2011_@_11h10m17s.txt" - this is perfect

But if I run this batch file as a Scheduled Task the log file is created as "logfile-03-10-2011_@_" No file extension and without the time stamp. Not acceptable.

I would really like to have the Time Stamp (and .txt extension) in the logfile name - the date wouldn't have to be in the exact time format.

How can this be accomplished?

Thanks in advance!!