Adding a custom INSERT query when adding a comment/post in Wordpress

I am goi开发者_C百科ng to be starting a project where a client has 2 sites - 1 built in Wordpress and 1 using a proprietary CMS. The client has a post category that exists on their proprietary site and they want to be able to post in this category and it to be added to a category on on the Wordpress site and vice versa. As far as I can see, this would be a fairy complex - especially as the comments would need to be synchronised as well.

Has anyone had experience doing anything like this?

I think you could do this very well using triggers (if available) to replicate the data.
I can't provide a more concrete tip, but I figure you'll find all the informationn you need, now that you know what to search for.

How complex it will be is rather dependent on how different Wordpress and the proprietary CMS are.

If one of the databases can reach the other, you could make use of Views.