Adding Bold Tags To Parts Of A String?

I'm trying to figure out a macro that will add b and /b tags around bold text. Bolded text can appear multiple times within a cell. I need it to run on all cells within a sheet.

So I need it to:
1. Search for bold strings within cells
2. Identify the length of the bolded strings
3. Add b and /b at the beginning and end of those strings
4. Repeat for all active cells

The only macro I was able to work out adds tags to only the last bolded string, whereas I need the tags on several non-continuous strings.