Pausing thread until other program/process finishes to run

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C#

Hello guys,
I've been trying to pause my main thread while the network drive is being mapped, but each time the time for network drive mapping is different. I don't want to use Thread.Sleep(<static number="">).
The program is as follows:

Thread T2 = new Thread(() =>
{
System.Diagnostics.Process.Start("net.exe", @"use Z: \\Server-Share\My_Files\");
}
T2.Start();
T2.Join();
File.Copy(@"C:\daily_files\Updated_data.xlsx", @"Z:\Updated_data.xlsx", true);

The problem here is that T2 starts the mapping of network drive, which takes 3-5 seconds and the next step in main thread is copy-paste file to that new share. And the copy-paste starts earlier then the network share mapping finishes - then I get error that location is not available... So - looks like the network share mapping is running in its own thread....
Does anyone know how to make main thread wait for the shared drive mapping to finish?

Thanks a lot guys!