How to increase the levels of an enumerated list

[griera]

Helo:

I am trying to increase the number of levels in a numbered list. By default I 
have 4 levels:

1. 

        (a) 

                i. 

                        A

I would like to have 6 nivels:

1. 

        (a) 

                i. 

                        A

                                <level 5>

                                        <level 6>

I try to enlarge the number of levels displacing to the right the mark of the 
line "Numbering" in the box Document -> Settings -> Numbering &TOC, but the 
number of levels does not enlarge. How to do that?

I am use the version 1.4.3 in debian stable.

Thanks in advance. Regards. G Riera.