How to obtain verbose and debug log from powershell, without modifying code

Hello, 

I have the following issue: In a Xenapp citrix environment, i have published some applications that run a powershell scipt from the server. This powershell script run an executable. Normally, uses connect and can start the program but sometimes it fails but nothing is written to the Event log and no information is logged. I would to have a extensive debug log of what happens when the user run this command, having a debug log (verbose) of the powershell scripts that run on the server. Is there any that can be added to the powershell command line  (that runs from Citrix command line console) to get the extensive debug log without altering the powershell code??

The command is:

powershell.exe -file C:\GTS\appname\foldernam\myscript.ps1   ANY PARAMETER?

Please help

Thanks in advance