Backslash found where operator expected at Test.pl line 2, near "Verit
+as\"
So, what have you done to remedy that error in line 2?
Perl is not Powershell and not cmd.exe. The for command has a different syntax in Perl. See perlsyn.
You will have to use Perl syntax to write Perl code, this also goes for file paths.
If you want to read output from a subprocess, you can use backticks (see perlop and readline):
my $command = "C:\\Program Files\\Veritas\\Netbackup\\bin\\admincmd>bp
+imagelist -A -media -hoursago 24>";
for my $line (`$command`) {
...
};