checking for the @ symbol

[charles]

i am writing a script that tests to see if an \@ symbol is entered by an
end user. i am trying to look at other alternatives that a malicious end
user might do to get around my checking. right now, i am doing a simple

        if ( $add_alias =~ /\@/ ) {

could an end user enter an escaped ascii character code that would be
interpretted as \@

thanks -cjm