Scripting Terminal Command with Automator
Here is a Automator task that can help you with.

1. Action: Get text
To do: Copy and paste desired text content.  



2. Action: New text file
To do: File format 'simple text'; save as 'automatortempfile.txt'; In Where is tricky, when you click will show a select folder location, press Cmd+Shift+g and type /var/tmp.  



3. Action: Execute Applescript
To do: Copy and paste this content.  

tell application "System Events"
    activate
    return text returned of (display dialog "Enter password" default answer "" with hidden answer)
end tell


This will open a dialog with a message "Enter password", that you must provide user password (this user must have admin rights, because this is required to write in /Library/* folder).



4. Action: Execute shell script
To do: Copy and paste this content.  

sudo -S mkdir -p /Library/LaunchDaemons
sudo -S mv /var/tmp/automatortempfile.txt /Library/LaunchDaemons/com.apple.launchd.limit.plist


First line: Create a folder LaunchDeamons if doesn't exist (just for ensure that folder exists).
Second Line: Move your created file automatortempfile.txt from /var/tmp folder to /Library/LaunchDaemons/ and rename it to com.apple.launchd.limit.plist.

sudo -S will read password from stdin.



Now, just save and use!