I am certified in Apple Motion Graphics, which is the Professional Application used to add subtitles to video. You can take a look at my work on my website [login to view URL]
I can deliver the finished content within 24 hours. In fact, if you get it to me within the hour, you might have it tonight (I live in the US).
I will need to know the video format you currently have to see if it is compatible and what finished format you need it to be in. If you don't know, just look at the file on your computer and tell me what the extension is. Example: .mov