I have some scripts where I'd like to separate their log output from the standard Sitecore Powershell log (SPE.log).
Is there a parameter which I can use on
Write-Log to output to a named log file?
You cannot. It doesn't support anything like that.
Here is a documentation of Write-Log cmldet.
If you are interested you can see how it is implemented:
SPE jsut defines it own log4net appender, see configuration here Cognifide.PowerShell.config (serach for
You would have to implement your own solution with dynamic appenders.
This might give you an idea of where to start: How to add log4net appender in runtime?