Example

[aemonge]

I'm trying to au BufRead,BufNewFile,BufReadPost *.html set filetype=javascript but I really don't know how to do it in the _vimrc_local.vim file. I've also tryied to do it in a _vimrc_local.html file, but seams not to work.

[embear]

I'm not really understanding what you are trying to do. I suspect you want to set the filetype to javascript for files contained in a specific directory/tree and matching *.html. To achieve this just add a file named .lvimrc to this directory/tree containing theses lines:

if expand("<afile>:e") ==? 'html'
  set filetype=javascript
endif

If this is not the answer to your question please go into more detail...

[aemonge]

That's exactly what I meant !!! Thank you so very much !!!