It also occurred to me that you would need to handle the error, if
it didn't find the Identifying value(actVal) in the column  you're
looking for it in, as in:

On Error Resume Next
Set fc = Worksheets("Sheet2").Columns("A").Find(what:=actVal)
fndIRrow = fc.Row
If Err.Number = 91 Then 'it didn't find it
'<---so, go the next one, or whatever you need to do
else
Sheets("Sheet2").Cells(fndRrow, 5).Value = newVal
'<---put the value where you want it, etc.
End If