You just set all environment variables pointing to 6.3.2 installation and run qde script with full path from 6.4 
installation (or from shortcut if you are on windows).
It should work.

Env variables, see http://community.qnx.com/sf/wiki/do/viewPage/projects.ide/wiki/IDEGeneralFAQ
(Which environment variables does IDE use?)

Also if you are on windows you can switch between instillation using qwincfg (that switches env variables for you, i.e. 
you switch to 6.3.2 but run IDE 4.5).

Edward Lee wrote:
> I need to run Eclipse plug-ins for the IDE that requires Eclipse 3.3 or later. Which means I will need IDE 4.5. But, 
my deployed targets are all running 6.3.x, and I do not want to have to upgrade them all.
> 
> If I try to execute binaries built for QNX 6.4 on a QNX 6.3.x system, I will run into library (libc) incompatibility 
issues. If I have both QNX 6.4 and 6.3.x installed on my host, how do I configure the IDE 4.5 to build software for QNX 
6.3.x?
> 
> _______________________________________________
> General
> http://community.qnx.com/sf/go/post16337
>