Locating exp920 executable

You'll have to install Oracle 9i on this database server if you want to run the executable on that server. However, so long as the server you have running 9i can connect to the server running 10g, you can use the Oracle 9i export utility on the other server and perform the export across your network. In your 9i ORACLE_HOME/network/admin directory, you will find a tnsnames.ora configuration file. You will have to add an entry to that file that looks like the following:

ora_10g_db =
   (DESCRIPTION =
     (ADDRESS_LIST =
      (ADDRESS =
         (PROTOCOL = TCP)
         (HOST = ora10ghost.acme.com)
         (PORT = 1521))
      )
     (CONNECT_DATA =
      (SERVICE_NAME = orcl)
     )
   )

You can call this tns alias anything you want. I called it "ora_10g_db," but you can use any meaningful name you want. You will also have to change the database HOST, the PORT of the Oracle Listener on that server and the database SID (SERVICE_NAME) to match the values specific to your Oracle 10g database. Once done, you can connect to that database with the export utility in your Oracle 9i server as follows:

exp userid=system@ora_10g_db file=.....

The "@ora_10g_db" tells exp that this is a remote database and to look up the connection information in the tnsnames.ora configuration file.