if statement microsoft excel- if column a has bold text then sum column c

Hi,

Here is what I am trying to do!

If the text in Column A1:A45 is bold, then sum the corresponding rows in Column C1:C45.

So if Cell A1’s text is bold, A5 is bold and A7 is bold, then add the value of cell C1, C5 and C7 together. Make sense?? THanks so much!