Whats the best and most efficient way to get a 32 bit plugin working in cubase 64bit
install it! 
No hard & fast problems generally, do as most others are (myself inc).Install both 32 & 64 bit, if you hit any problems with jbridge/bit bridging into 64bit, use 32 bit for the instrument/plug etc…I generally use 32 bit for rewire apps (ableton & reason) then switch to 64 bit for more hungry plugs like Omnisphere!..(The whole shebang only costs you around 4gb extra hard drive space…and I just look at things as I have a “backup” copy of Cubase incase I hit a problem (opening a project etc).
its quite cool to have both installed and you will find what works & what doesnt with any serious grief. 
ok, i already have both of them installed, but i dont see some of my 32bit fx in the 64bit version of cubase,
In Win64, 64bit applications are installed in "C:\Program Files", while 32bit applications are installed in "C:\Program Files (x86)".
Your 32bit VST’s are probably installed in “C:\Program Files (x86)”, so check in your Cubase x64 if that path is added to the list (Device → Plugin information). I don’t think it’s included by default (not sure though).
dirkpiano, your right, i guess i got confused seeing some forum posts about jbridge and such, just loaded nexus in cubase 64bit!