OCI8 libraries (some errors fixed, some more remain)

I posted a thread about errors I had installing OCI8 libraries on
Solaris 10 Sparc machine. I don't have root access.

I finally managed to fix that error by editing rbconfig.rb file and
correctin 'cc' path there. It had gcc path in there. I installed Sun
Studio 12.1 and replaced that path. So, at-least that error was fixed.
Now I have this error and I kind of know how to fix it but I don't
know which file to edit.

****ERROR MESSAGE**************
bash-3.00$ cd ruby-oci8-1.0.6
bash-3.00$ ls
ChangeLog doc Makefile pre-
distclean.rb ruby-oci8.spec test
config.save ext metaconfig
README setup.rb th-instant-client
dist-files lib NEWS ruby-
oci8.gemspec support VERSION
bash-3.00$ make
ruby setup.rb setup
---> lib
---> lib/dbd
<--- lib/dbd
<--- lib
---> ext
---> ext/oci8
/usr/ccs/bin/make
setup.rb:476: warning: Insecure world writable dir /opt/coolstack/lib/
ruby in PATH, mode 040777
/usr/bin/cc -I. -I. -I/opt/coolstack/lib/ruby/1.8/sparc-solaris2.10 -I/
export/home/roradmin1/ruby-oci8-1.0.6/ext/oci8 -DRUBY_EXTCONF_H=
\"extconf.h\" -fPIC -O3 -fPIC -I/opt/coolstack/include -I/export/home/
roradmin1/oracle/instantclient_11_1/sdk/include -c oranumber.c
"/export/home/roradmin1/oracle/instantclient_11_1/sdk/include/math.h",
line 47: cannot find include file: <stdcomp.h>
"/export/home/roradmin1/oracle/instantclient_11_1/sdk/include/math.h",
line 58: cannot find include file: <cmath>
*** Error code 1
make: Fatal error: Command failed for target `oranumber.o'
Current working directory /export/home/roradmin1/ruby-oci8-1.0.6/ext/
oci8
'system /usr/ccs/bin/make ' failed
Try 'ruby setup.rb --help' for detailed usage.
*** Error code 1
******************ERROR MESSAGE END***********************

Error is because it can't find: <cmath.h> etc. I know where they are
in my system, but I don't know where to add that path information. The
makefile doesn't have many options. What file do I need to edit to add
path information of .h files?