question about MFC

[JR]

Hey, In MFC using Visual studio i make a dialog box, with 4 text box controls.
1. How do you change the font of the text in the box to a different colour.
2. How would i check for validity, for example one text box only contains letters, and no other characters.
3. how would i update the 4th textbox which is read only with a new string.

I've tired to look everywhere but mfc is old and there isnt alot of information about it.