Psexec, cmd and batch

Hello.

 I have a batch file named a.bat on a winserver2008 Desktop.
That batch file only write the SessionID (from environment variable) to a local eventlog.

I want to execute it remotely using cmd (otherwise the SessionName doesn't appear).
so I have tried
<code>c:\PsTools\psexec.exe \\<Server> -u test2 -p <Password> -i 2 cmd "c:\Users\test-2\Desktop\a"</code>
or

<code>c:\PsTools\psexec.exe \\<server> -u test2 -p <Password> -i 2 "cmd \"c:\Users\test-2\Desktop\a\"";exit</code>

all of these just open a terminal on the remote machine but don't execute the batch.
Any ides?

Best Regards,