I want to be able to place a plus sign (+) in front of a positive number
The plus sign is meant to amplify the positive value. So far, I have only found this formatting for negative numbers.
Use this custom format:
Or adjust to suit. Using the "+" does not even require the "\+" approach. Excel strips off the "\" from it. If you'd like to add a space after it, Excel's fine with that too (so instead of "+24" you'd have "+ 24").
The real trick is to specify the first three kinds of formatting. Those are for numbers. If you don't, Excel will handle them normally AND then add a "+" to them. So -28 would be: -+28.00 and I bet THAT is not desired! If you like the idea of "+0.00" you can just specify the first two formats, positive and negative, and leave the last two, zeros and text, alone.