Splunk setup must be executed on the target machine, you can use a network driver to copy the file on a server but you cannot execute it on the remote server!
This is because Splunk installation starts some processes on the target server, it isn't only a copy of files.
You have only two ways:
ask to the server administrator to install Splunk UF,
find a different way to take logs (e.g. WMI), but I don't like it!