We are must going in another way...
I solve my problem in another way. May be this will be usefull for another men who using Tk Fbox.pm and need using utf-8 filenames.
I must using Tk and Wx in one code.But from Wx I use only Filedialog. Why I must use Wx FileDialog?
Because Tk has embeded problem with UTF-8 filenames. It shows in IconList dialog broken filenames if codepage of filenames different than iso8859-1...
If I use in my code

use encoding 'utf8';
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then IconList shows true but I can't choose folders with utf8 names and choosed filename in filedialog shows as ?????.???
In end of page http://search.cpan.org/~srezic/Tk-804.029/pod/UserGuide.pod I find this:
Unfortunately, there are still places in Perl ignorant of Unicode. One of these places are filenames. Consequently, the file selectors in Perl/Tk do not handle encoding of filenames properly. Currently they suppose that filenames are in iso-8859-1 encoding, at least on Unix systems. As soon as Perl has a concept of filename encodings, then Perl/Tk will also implement such schemes.
Early I can't resolve this problem but after You hint for MyMenuButton module(http://www.perlmonks.org/?node_id=866575) I get method how I can resolve my problem.
I found this:
1. If I remove all about encoding in FBox(it has only 8859-1 codepage support).
2. If I add in FBox module

use encoding 'utf8';
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then all works fine.
By Your method I insert new MyFBox module in my code. And some corrects in fdialog design for my wishes. I can adding some png pictures instead standart bitmaps...
Thank You for help!