No, the command line only allows you to set the default forward server with the splunk add forward-server command but does not allow you to set up custom tcpout stanzas like the above. If the issue is you can't edit the Splunk\etc\system\local\outputs.conf since it's telling you it's read only, you can copy the existing one on to your Desktop, edit it, and then overwrite it in the original location assuming you have Administrator privileges. After, you'll need to restart the Splunk service in order for it to change the settings.
If the issue instead you need to do everything from the command line for a script or such, you'll have to script something that works with the outputs.conf file directly rather than trying to interface with Splunk at the command line.
