Already installed ffmpeg, how to add libvpx after the fact

Question

I have ffmpeg already installed on my server for the past 6 months, everything works fine but now it seems I need libvpx to be added to it so I can encode webm files. Is it possible to add this to my current ffmpeg or does it need to be removed and rebuilt from scratch?

My current ffmpeg setup looks like this -

ffmpeg version N-35515-g901af94-syslint, Copyright (c) 2000-2011 the FFmpeg developers
  built on Dec  6 2011 20:05:55 with gcc 4.1.2 20080704 (Red Hat 4.1.2-51)
  configuration: --prefix=/usr/local/cpffmpeg --enable-shared --enable-nonfree --enable-gpl --enable-pthreads --enable-libopencore-amrnb --enable-decoder=liba52 --enable-libopencore-amrwb --enable-libfaac --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid --extra-cflags=-I/usr/local/cpffmpeg/include/ --extra-ldflags=-L/usr/local/cpffmpeg/lib --enable-version3 --extra-version=syslint