You can do it a couple of different ways. Text won't ever actually appear on top of a sprite unless the image has the text incorporated into it. However, you can overlap 2 sprites, one that is text only with a transparent background and one that is you srpite image. The text sprite has to be created after the image sprite so that it has priority.
Another way is to use PASTE SPRITE while hiding the original sprite. Once you paste the sprite, it becomes an image and you can just put text directly over it. Check out the following link. Near the end of the thread I post an example that shows a method of text on sprite including sprite priority:
Text on Sprite
Enjoy your day.
