Don't know for sure, but lots of routers have have the PorterCable base pattern. Some have it despite also having a proprietary one. So check that first. Last time I did this I taped a piece of fairly heavy paper to the base, punched it through the openings, then used that as a template for drilling the holes. But since you're installing the router to a plate, you may be able to use a punch of some sort directly through the router base, then drill on the marks. Turned out just fine. Most pre drilled plates have countersunk holes so the bolt head doesn't snag your work.
The more I do, the less I accomplish.