I agree with RCMZZ, you will have to test.
To simplify, I would suggest you first quit trying to copy the file and modify your script to run everything from one directory where all files exist. After you get that working, then you could always trying adding in the copy of the file and the long file/directory names which are going to require quotes.
One thing you have to keep in mind with scripting languages and executing commands is quotation marks. You have a path to the agent-cert.ssl file which (if you have already copied the agent-cert.ssl file to the location in the SSL_CERT_FILE= paramter is going to have a space in the file name (in more than one place). If you don't have quotes setup on the commandline for powershell you could get a syntax error. I would suggest you put the command in a batch file (.bat or .cmd) and get it working. You may then be able to migrate to Powershell, but keeping quotation marks in mind.
As we pointed out earlier, you will probaly want to delete , then run the command, then look at the file %temp%\install_csp.log for errors. If %temp%\install_csp.log is not getting created you are likely running into a syntax issue with the Command line (Powershell, .bat, etc...) and the command is not running.
I don't know Powershell well enough to know if you are going to have major syntax issues with the spaces in the directory names or not. I would think it could be done, but there may be extra work to make it work correctly. Good luck !