How Do I: Convert a list of Lat/Long|X/Y coordinates into points in an image?

[Master TMO]

Here are the results in an Excel graph plot. I wrote a VBA routine to try and build believable random tectonic plate boundaries. It's very slow to run, a couple of hours, but then this laptop is not necessarily the world's most powerful computer. There are ways I can speed it up, and I still want to add directional and speed arrows for each of the plates, so it's not quite finished yet.

This would have been a helluva lot easier if I knew spherical trigonometry. I assume I covered it during getting that BS in Math, but I've never used it since and didn't remember any of it. Fortunately I was able to eventually find everything I needed online once I figured out what terms to search for. If anyone else wants to delve into the topic, I suggest looking for an aviation navigation page - all the formulas you could ever want are listed out right there, already put into a form perfect for doing calculations based on a planetary surface. I've actually had the general process in mind for a month or more, but didn't know how to implement it until I started finding the right equations.

Any critiques or suggestions from the geologically-knowledgeable crowd out there?