The multiple bin thing is definitely very odd. All it is doing is pointing to $ORACLE_HOME/bin in a convoluted way. You could go on forever though with iterations of ../bin/.
I'd expect the first line of the script to just read:
CONC_PROGRAM_ID=`$ORACLE_HOME/bin/sqlplus -s $FCP_LOGIN <<END
Although ideally the PATH variable would contain $ORACLE_HOME/bin in which case you could just use
CONC_PROGRAM_ID=`sqlplus -s $FCP_LOGIN <<END
Thank you. This is exactly what I was thinking about multiple bins.
Thank you very much.