There's no way to create a font, per se, directly out of Photoshop, so I'll answer based on what Photoshop can do, which is create images. This is an adaptation of a trick I picked up from the brilliant Angie Taylor, of After Effects fame.
Make a text file with something like "characters" on the first line, and one character on each line below.
Set up a Photoshop file that is the size you will need for your characters.
Create a text character, centered on the layer, and style it the way you want it.
Define a Text Replacement variable (
image > variables > define), naming the variable using whatever is on that top line of the text file, and import your text file as the dataset.
File > Export > Data Sets as Files
You will have a collection of identically-sized files you can then a) load into layers (via Bridge
Tools > Photoshop > Load Files into Photoshop Layers...) and turn into a sprite sheet using Horatio's script, or b) assemble as needed in your project.