SOLVED!!!
Pretty easy I've to admit, tested with Gentoo (HN and VE):
1) in HN lsusb to identify numbers relative to the usb port and the attached printer
Bus 008 Device 005: ID 04b8:0005 Seiko Epson Corp. Stylus Printer
Bus 008 Device 001: ID 1d6b:0001
2) in VE go to /dev/bus/usb, create a directory equal to the Bus number and create there with mknod 2 devices: 1 for the usb port and 1 for the pritner with the same device number in HN
crw-rw-r-- 1 root usb 189, 896 Nov 26 08:58 001
crw-rw-r-- 1 root usb 189, 900 Nov 27 12:29 005
3) now create in VE a device similar to the one in HN for the usbprinter and a link if needed:
crw-rw-rw- 1 root lp 180, 0 Nov 7 19:32 lp0
lrwxrwxrwx 1 root root 7 Nov 26 17:51 usblp0 -> usb/lp0
4) time to add devices permission on your VE configuration file:
DEVICES="c:180:0:rw c:189:896:rw c:189:900:rw"
5) start the VE end enter, with lsusb you should see both devices: the port and the printer
6) Cups should find the printer attached to the usb port
Good Luck 