Problem installing ROracle package under R

[Vittorio]

Context: Pentium 4 with FreeBSD 5.4 and R 2.2.0

I'm trying to install 
the package ROracle under R.
To start with I installed the oracle8-
client from the ports and referred to it via the variable $HOME_ORACLE 
as /usr/local/oracle8-client. Then I started R. After issuing install.
packages("ROracle") R downloaded the needed package and started to 
compile it but complained:
...............................
downloaded 
138Kb

* Installing *source* package 'ROracle' ...
creating cache .
/config.cache
checking how to run the C preprocessor... cc -E
ROracle 
configuration warning:
Oracle pre-compiler proc not in 
/usr/local/oracle8-client/bin/proc
you may not be able to compile 
ROracle

"/tmp/oraLibs2442.mk", line 2: Could not find 
/usr/local/oracle8-client/precomp/lib/env_precomp.mk
make: fatal errors 
encountered -- cannot continue
updating cache ./config.cache
creating .
/config.status
creating src/Makevars
creating src/Makefile
** libs
R 
CMD COMPILE RS-DBI.c
cc -I/usr/local/lib/R/include  -
I/usr/local/include -D__NO_MATH_INLINES  -fPIC  -O -pipe -
march=pentium4 -c RS-DBI.c -o RS-DBI.o
proc CODE=ANSI_C MODE=ORACLE 
INCLUDE=/usr/local/lib/R/include  PARSE=NONE LINES=false RS-Oracle.pc
proc: not found
*** Error code 127

Stop in /tmp/R.INSTALL.
C0fZy6/ROracle/src.
ERROR: compilation failed for package 'ROracle'
** 
Removing '/usr/local/lib/R/library/ROracle'

The downloaded packages 
are in
        /tmp/RtmpRLVjrq/downloaded_packages
Warning message:
installation of package 'ROracle' had non-zero exit status in: install.
packages("ROracle")
...........................................

So 
various directories and relating programs are missing! What else should 
I install to make ROracle work?

Ciao
Vittorio