Hi!
If you have HP-UX box (Unix clone as I know), so how WINDOWS .dll will work on it?
So, you need Oracle client installed on your HP-UX box (libraries, headers, etc), PHP source, cc (gcc), etc... When you will be configure PHP don't foget to include --with-oracle=[ORACLE_HOME] --with-oci8=[ORACLE_HOME]. Then make, make install, so on.
Or, if I wrong, use php_oci8.dll. php_oracle.dll is for Oracle 7. Plus, you must begin with oci_....(). Read manual.
Sorry for my English, but I hope you understand.
Sartorius.