Turns out the MAX7219 actually has the character generator to drive 7-segment common cathode displays - but only with digits "1" to "9", "-" and the characters "E", "H", "L", "P" in Table 5 (useful for spelling "HELP"). If you want other characters, you will have to code all characters yourself.
Wiring is given in the "Typical Application Circuit" on the first page, various other information including the current-setting resistor value according to how many active digits there are.
Nick, you need to put "<a name =" links into your pages so you can reference individual sub-topics.