How can I add syntax highlight all *todo.txt files?

[buscon]

Hi,

I have different todo.txt files for different projects and I would like to keep them separated.
todo.txt-vim highlights the syntax only if you open a file with the name "todo.txt".
I would like the plugin to highlight all files which ends with "todo.txt", in regular expression would be "*todo.txt".

Where can I add such feature?

thanks.