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

If there is some condition that makes the cells bold then perhaps you could use formulas however if the cells are manually made bold you are stuck using a UDF. In a module place the following code

Function sumBoldCells(sumRng As Range) As Double

    Dim ifBold As Range
    For Each ifBold In sumRng
        If ifBold.Offset(, -2).Font.Bold = True Then
            sumBoldCells = sumBoldCells + ifBold
        End If
    Next
End Function

Then to use the formula-> =sumBoldCells(C1:C45)

While you can do this with VBA I would just use a SUMIFS() and a helper column (it is a lot simpler). Put a 1 in the helper column next to the required amounts and then 'sum' the amts using SUMIFS(). This has the advantage that you can use the technique at any time (you don't have to have your code available) using a built-in Excel formula. Also you can have more than 1 group because you are not just using a True/False (only 2 outcomes). Also you do not have to alter the formating (although you could).

on where/when it pops up. Are you in the VB editor or in the worksheet? I really don't think the difference between 2007 and 2010 would matter wrt code...