I'm not sure what you mean. I can guess you'd mean one of these.
in reply to Re^3: System command using array and pipe
in thread System command using array and pipe
Store the shell literal in the config.
my $password = '...'; # Not the password, but a shell literal of the
system( ... "-p$password" ... );
Pretend the config is a shell literal.
my $password = '...';
system( ... "-p$password" ... ); # Pretend $password is a shell liter
Embed the config data in the command
system( ... "-p..." ... );
Every one of these are very unappealing to me.