This is probably not possible, but I figure there's not harm in asking.

I know that if I have a cell containing "apples and oranges" and I highlight
"apples" and click the bold button, only "apples" will be in bold face and
"oranges" will stay regular. Is it possible to do this with a formula. What I
mean is this:

A1="apples "
A2="and oranges"
A3=A1&A2

Is there any way that in A3 only "apples" be in bold face?

Alex