Nonstandard path for includes/libraries?

[Alex]

Hi,

I am trying to attempt many non-standard things... I would like to install 
gcc to a non-standard path and use nonstandard paths for 
binutils,glibc, and kernel headers... [And I would prefer to keep them in 
separate directories]

Installing gcc to a different path is easy enough, and editing the 
specfile for changing the path to ld-linux.* is easy enough.   But 
changing the default search paths for system headers & libraries has me 
stumpted.  I couldn't find any documentation about this.

I realize there are pre-made scripts for building an entire toolchain, but 
they do not do what I'm trying to accomplish.

So, is there a proper way of changing the default header & library paths 
for gcc?

Thanks

-Alex