So now it is done.
I applied the glow to the calligraphed text from the GIMP (using a plug-in for layered effects found on the net... It was indeed simple) and imported the result in CC3.
I think I will now post it in the Finished Maps section with some background details, as this thread is already probably overstretched for an introduction post.
Thank you everybody for all the advice. I enjoyed very much doing this first map. This exercice gave me the interest in practicing both calligraphy and mapping again!