@lines = (
"0|aa aa|1998|aaa a|a aaa|10|aa a aa",
"1|bbb aa|1992|fa a|gaa|5|gfsa aa",
"2|aa ba|1997|afa|hhaa|1|asdf aa",
"3|cccaa|1997|ssa s|hhava|3|gfdh gaa",
"4|adaa|1994|g a a|jiua|6|angf a"
);

@lines = sort {lc(($b =~ /(\|[\w\s]+){2}/)[0]) <=> lc(($a =~ /(\|[\w\s]+){2}/)[0])
     } @lines;

foreach $line (@lines){print "$line\n";}