Capture ALL (stdout, stderr AND CON) output of cmd executing plink

Hi all,
 
its my first time posting a coding question.. I am getting crazy with the following case (searching the internet for a couple of days):
I want to open SSH connections from c# via opening a process and running plink. All output should be collected and depending on the results the program will fire actions to the ssh.
My big problem is, that i am using a couple if different scripts and i need user interaction. therefore i have to capture ALL output data (standard output, standard error AND CONSOLE).
 
Looking at the following test batch should make the case more clear:
1: @ECHO OFF
2: ECHO StdOut
3: ECHO StdErr 1>&2
4: ECHO Cons>CON
 
I am able to capture lines 2+3, but not 4 (used by some programs).
I have also tried powershell instead of cmd.exe as starting point, but same result.
 
Is there any way in c# to capture the console out as well or do you know any third party command line being able to redirect CON out to stdout or something like this?
 
any help is really appreciated. Thanks a lot!
Michael