MySQL version issue

As some of you will recall, I enquired on this list about versions of MySQL and PHP a while back regarding and issue wit using the 'ON DUPLICATE KEY UPDATE' command in MySQL INSERT queries. Having upgraded our in-house system to PHP5 and MySQL 4 the issue was no longer a problem. However I have subsequently enquired with our out-of-house web host and they are still using PHP 4.1.2 and MySQL 3.25.58. As one of the purposes of asking them was to establish if I could easily upload from my database to the remote database, I now have a problem. I was planning to use a compare and update script that used 'ON DUPLICATE KEY UPDATE' command in MySQL INSERT queries to add or change items on the remote server. However I can't, as it's a MySQL4 feature and the database to which I am writing ain't using MySQL4! Any ideas about how I can create a MySQL3 compliant substitute for the 'ON DUPLICATE KEY UPDATE' Query action? -- Mark Benson http://homepage.mac.com/markbenson