Code:
Connected to:
Oracle9i Enterprise Edition Release 9.2.0.5.0 - 64bit Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.5.0 - Production

SQL> def today="14/02/2006"
SQL> spool myfile&today..log
SP2-0332: Cannot create spool file.
SQL> prompt  myfile&today..log
myfile14/02/2006.log
SQL>
SQL> spool myfile.log
SQL> spool
currently spooling to myfile.log
SQL> spool off
SQL>
I guess there is no subdirectory "myfile14/02" to put "2006.log" into.