I tried this, all it did was open a cmd prompt with "cmd -c (my command)" and didn't actually run it. see below.
C:\windows\System32>cmd -c (powercfg /lastwake) Microsoft Windows [Version 6.1.7601] Copyright (c) 2009 Microsoft Corporation. All rights reserved.
C:\windows\System32>
***Update
I changed my .bat file to read "cmd /k (powercfg /lastwake)" and it worked.
You can also leave out the () and it works too.