I have all of Plato's works, but unfortunately they're missing the Stephanus numbering. Is there a resource which I can use to see which paragraphs they refer to? A brief table containing the first few words would be good enough!
This online website has a fairly exhaustive listing of online versions of Plato's dialogues. Most of the English translations will have the numbers listed, definitely the Perseus ones. This site also discusses the same issue and provides more (though largely overlapping) suggestions.
If the dialogues you need are there, then hopefully that solves it. Otherwise I can point you to this list which at least tells you which dialogues are in which Stephanus number range.
Short of taking out my Complete Works of Plato and reading you the numbers to passages I think that might be the best I can do. Good luck!