Buscar padrão em intervalo de linhas no vim

http://vimdoc.sourceforge.net/htmldoc/vimfaq.html

11.22. How do I search for a pattern within the specified range of lines
       in a buffer?

You can search for a pattern within a range of lines using the \%>l
and \%
For example, to search for the word 'white' between the lines 10 and 30 in
a buffer, you can use the following command:

    /white\%>10l\%<20l

For more information, read

    :help /\%l