I get an Excel spreadsheet with 5K race times that look like this:
18:29.3
18:29.7

I need to change them to look like this:
0:18:29
0:18:29

I have tried the find with this:
([0-9]{2}):([0-9]{2}).([0-9])

thinking I could then use a replace like this:
0:\1:\2

However, the find always comes back that no cells meet this criteria. I have
also tried a find with **:**.* and nothing is found. If this approach worked,
what would the replace string be?

I get hundreds of these times and an automated way of changing them would be
very helpful. Thanks in advance.