Using multiple compilers

["J.B. Brown" <brownie at csserver dot evansville dot edu>]

Hello, and thank you for your time.

I have a question regarding multiple builds of GCC on the same machine.  I 
am not the system administrator on a supercomputing cluster used at the 
National Institutes of Health (NIH), but have access to the cluster.  It 
is a Red-Hat Linux based cluster, with an older version of GCC (2.9 or 
so).  I downloaded and successfully built GCC 3.3 .  However, I am not 
sure how to tell programs (namely compilers and make environments) to use 
the newly built 3.3 include files and libraries, instead of the old 2.9 
libraries.

For example, if I have hello.cpp:
#include <iostream>
int main(){cout << "hello";return 0;}

I want it to use the include files from GCC 3.3 (locally at 
/data/pkg/gcc/include, and not from 2.9, which 
are installed at /usr/include on this particular system).  This is true 
not only for iostream, but all of the standard includes and libraries.
Specifying the -I/<dirname> was not successful.

Can you tell me how to either
a) modify my environment to no longer point to /usr/include and to my 
directory instead,
b) recompile GCC 3.3 again with a flag to specify where the includes and 
libraries are, or
c) Define some sort of symlink for my account to reference my GCC 
directory and not the default GCC directory?

Any and all help is greatly appreciated!
Sincerely,
J.B. Brown