Follow wiser advice Ppeoc but be aware of the oneliner solution (pay attention to the win32 doublequotes)
It is possible and simple hardcoding your search:

perl -lanF", " -e "print join(',',map{$1if/(?:[Name|Age|Gender] = )(.+
+)/}@F) if shift @F eq 'Person1'" persons.txt

Lydia,20,F
[download]

But is also possible to parametrize your oneliner with a BEGIN block that pop @ARGV to get two parameters and leave in it the file to feed to perl -lan. A custom delimiter for autosplit is specified with F", ".

perl -lanF", " -e "BEGIN{map{$_=pop @ARGV}$rx,$who}print join(',',map{
+$1 if /(?:[$rx] = )(.+)/}@F) if shift @F eq $who" persons.txt Person1
+ "Name|Age|Gender"

Lydia,20,F
[download]

All theese jems and much more are shown in perlrun

Hth and have fun!
L*