Charles has appeared in multiple fictional works. This is an ongoing list of all fictional portrayals I can find.
Novels
Crown in Candlelight by Rosemary Hawley Jawman
The Golden Porcupine by Muriel R. Bolton
Frost on the Rose by Maureen Peters
The Heron's Catch by Susan Curran
In a Dark Wood Wandering (Original Dutch title: Het woud der verwachting) by Hella S. Haasse
I Return: The Story of Francois Villon by Doris Leslie
The Maiden's Tale (Sister Frevisse, #8) - by Margaret Frazer.
My Lady, My Love by Gladys Malvern
The Unravished Bride by Terry Tucker
Shakespeare
Charles also appears as the Duke of Orleans in William Shakespeare's Henry V. The actor playing Charles is in bold. While obviously not an exhaustive list of every performance, I've included versions that are readily available on home media.
RSC Henry V (2015) dir. Gregory Doran - Nicholas Gerrard-Martin
The Hollow Crown: Henry V (2012) dir. Thea Sharrock - Stanley Weber. Oddly, Charles is inaccurately portrayed as dying at Agincourt.
Henry V (1989) dir. Kenneth Branagh - Richard Clifford
BBC Television Shakespeare: The Life of Henry the Fift (1979) dir. David Giles - John Saunders
An Age of Kings: Henry V: Signs of War and The Band of Brothers (1960) dir. Michael Hayes - Jerome Willis
Henry V (1944) dir. Laurence Olivier - Francis Lister
Other Films
Je, François Villon, voleur, assassin, poète... [I, François Villon, Thief, Assassin, Poet] (2011, TV, France2) dir. Serge Meynard - Jean-Gabriel Nordmann