Call a function on error

This is in 2003.

So, I have a large arsenal of workbooks acting as templates and front-ends to databases. It's gotten to the point where I need to keep an automatic error log. I've created one in the form of an add-in. My plan was to have at the top of my functions I would have something to the likes of:
On Error Call errCatcher.sendError(...)

This obviously doesn't work and I don't really want to have to add an in-function error handler in EACH one of my functions that then JUST calls errCatcher.sendError().

My question is if it's possible to either change how the default error handler handles errors, or if I could create a global error catcher. Or if there's a more efficient option to the ones previously mentioned.

Thanks.