How to install Logme123 client silently and provide all permissions for remote support?

Here is the use case:

• - We have servers that non-IT staff don't have login access
• - An application is running on the server
• - From time to time, we need vendor support to troubleshoot the application
• - At this time, IT needs to sign into the server, use the code vendor support provided, install logmein123 client, and grant vendor support remote access
• - This business runs 24x7, and IT cannot be readily available 24x7

So, the company IT needs a way to

1. - Give non-IT staff access to install logmein123 on the server without logging into the server
2. - During the installation process, automatically embed the 6 digit codes provided by vendor support and grant all permission
3. (Optional) Kill the session after vendor support completes troubleshooting --- vendor support always does it. So, it's optional, not a requirement.

I have written a PowerShell GUI that runs psexec from a controlled environment that staff has access. I can use psexec to install logmein. But how to do #2 above (the 6 digital codes & permission)?

Thanks.