# Given $record
my %record;
@record{ qw/account address info/ }
    = unpack 'A20 A42 A255', $record; # adjust widths to suit

# ($record{'account'}) = $record{'account'} =~ /^(\d[\d ]*)$/ 
($record{'account'}) = $record{'account'} =~ /^(\d+)$/ 
    or die 'Bad Account ID';    # detaints, too
# verify the rest