Were you using excel to translate their data to the map, or some external script to create the file? If it's the latter, why not use a plotting library? If it's the former, how did you acquire this unholy power?
I believe you, but isn't it baffling that your superiors couldn't recognize that giving you access to some Python or whatever would vastly improve your productivity, what you produce, and your happiness, all for a grant total of €0 and some de-rigidifying of arbitrary rules?
But also, thinking about this a bit more, doesn't excel have the ability to plot geographic data?