Aligning a footer on the outside text margins

Does anybody know how to align an header/footer on the outside of the text margins? For example:

\fancyfoot[LO]{\footnotesize \thepage~{\color{red}\vline}}
\fancyfoot[RE]{\footnotesize {\color{red}\vline}~\thepage}


What I want is to fix the position of \vline on the text-width, and make \thepage left (or right) align on the outside.

\fancyfoot[LO]{\footnotesize\leavevmode\llap{\thepage~}\textcolor{red}{\vline}}