Below are some examples illustrating the use of the command line. Simply select the conversion you are doing, and modify the example to suit your specific needs. The examples listed are a subset of what can be done, but the most popular. If you don't see what you are trying to do, select the closest and work from there.
Example: PPT to Text File Conversions
Example: PPT to Various File Format Conversions
Example: HTML to Various Format Conversions
See also:
Using 'Convert PowerPoint' - Command Line
Helpful Hints For Creating a Command Line