$_ = 'FDR [62.10060.051-F] [62.10051.381] 0 1 0';
  @f1 = split/\s+\[/;    #>> split only \s+ AND [ ...
  @f2 = split/\s+\[?/;   #>> split \s+ OR \s+[ ...
  @f3 = split/\]?\s+\[?/;   #>> split parts, without []...

  print join(" + ", @f1), "\n";
  print join(" + ", @f2), "\n";
  print join(" + ", @f3), "\n";
__END__
FDR + 62.10060.051-F] + 62.10051.381] 0 1 0
FDR + 62.10060.051-F] + 62.10051.381] + 0 + 1 + 0
FDR + 62.10060.051-F + 62.10051.381 + 0 + 1 + 0