I don't see why not.
We have some powershell scripts that we just kick off by way of a batch file. So get a working batch file that runs your powershell the way you would expect, then put the batch file in Splunk at whatever internval/sourcetype whatever you like in Settings>>Data inputs>>Scripts.
Or maybe under
Powershell v3 Modular Input
Settings>>Data inputs » Powershell v3 Modular Input.
Maybe, maybe not. If your powershell/batch executes and writes out to a text/log file but does not echo it to console then Splunk will ingest the command, and the output of the command.
and that should be it.
You can then tell the file monitor portion of Splunk to read the output file log if you so choose.
If the scripts output verbosely to the console then Splunk will probably pick that up.
I've not done Windows batch in a while or powershell scripting much at all, but I think you would want your file to do the Linux equivalent of
>dev null if you don't want Splunk to pickup the actual script output.