Do you have Photoshop, or GIMP? Or did you have another photo editing programme? If you don't, GIMP is free and works much like Photoshop (unless they've made drastic moves away in recent years, I haven't used it in ages D:).
You'd open up a blank document in either of those programmes, make sure the background is turned off, and type in your text in the font you want. Then crop if necessary and save it out as a PNG or GIF. (If it's one colour, GIF would actually be better, in retrospect. I was on my mobile for the above comment and so I had to be a bit abbreviated. Sorry about that!)
URGH sorry. Reposted for correction of link. Where is my BRAIN tonight?!