The fact that the script runs successfully indicates to me that you have defined the 'Run As Administrator' part correctly
I really am not going to be able to tell you much as to why nothing is being output to the file. If you leave out the
> C:\batch\output.txt
part, do you get any output? I would expect that you would get something to run to Standard output. If not, I think that is your answer. You are not seeing anything in the file because nothing is output
I'm not sure of what could be done from a Data Protector perspective. Maybe make sure that the file is created before the pre-exec script runs, or use the >> mark instead of > to Append
You may be able to get better information from the other folks on this Forum