Option Explicit
Sub test()
Dim s As Byte, y As Integer, c As Range
If Not IsDate(ActiveCell) Then Exit Sub
s = DatePart("ww", ActiveCell.Value, 2, 2)
y = Year(ActiveCell.Value)
Set c = Rows(1).Find(y, Range("A1"), xlValues, xlWhole, , , False)
If Not c Is Nothing Then
Set c = Rows(2).Find(s, c.Offset(1, -1), xlValues, xlWhole, , , False)
If Not c Is Nothing Then MsgBox c.Column
End If
End Sub