RHAW 2.1, gcc and libstdc++ question

Hi there,

I'm currently running RHAW2.1 on a hp workstation. gcc 2.96 is the 
default compiler with this distribution but there are gcc 3.0.4 packages
available too. Once gcc 3.0.4 with all the needed components (mostly new
libstdc++3) are installed on my system, how can I make it the default
compiler (I mean, are there system wise configuration files to do this
or not)? When compiling using gcc 3.0.4 (actually gcc3 command), how can
I target my source code to include and link against the new libstdc++3
and not libstdc++ library (provided with the gcc 2.96 packages)? By
default, it seems even gcc3 includes and links against the old library
(for example, I get an error at compilation time when using
numeric_limits that are defined in libstdc++3 but not in libstdc++).
Same question as above: is there a way to make libstdc++3 the default
C++ library? If the only possibility is to explicitly target the right
libraries in Makefiles, it would become very problematic to use KDevelop
for development because Makefiles are automatically generated without
user assistance by the IDE.

Thank you for your help.