Dim sheet As Worksheet
Set sheet = Sheets(SheetName)

    strSearch = ColumnName

    Set aCell = sheet.Rows(1).Find(What:=strSearch, LookIn:=xlValues, _
                LookAt:=xlWhole, SearchOrder:=xlByRows, SearchDirection:=xlNext, _
                MatchCase:=False, SearchFormat:=False)

    If Not aCell Is Nothing Then
        GetColumnAddress = aCell.Address
    Else
        GetColumnAddress = "$A$1"     'Error!
    End If