Altiris has a lot of connector, and you should be able to expose the data you want out via scheduled file exports, web-services or direct database connectivity.
However Excel file format is _not_ a good option to export data. It's arguably a good file format for presenting it ;), so it should be at the end of the data chain (close to the consumer, which is not likely to be your service desk tool, is it?).
You can also export the data to CSV, which can be read by Excel.