Option Explicit

Sub ImportData()

Dim HistoryTool As Workbook
Dim CWB As Workbook
Dim TargetSummSheet As Range
Dim cls, LR As Long, i As Long

Set HistoryTool = ActiveWorkbook

cls = Array("C3", "C4", "C5", "C6", "C10")

With Application.FileDialog(msoFileDialogOpen)
    .Filters.Clear
    .Filters.Add "Excel Files", "*.xlsx*;*.xlsm*;*.xlsa*;*.xm*"
    .AllowMultiSelect = False
    .Show
    If .SelectedItems.Count > 0 Then
        Workbooks.Open .SelectedItems(1)
        Set CWB = ActiveWorkbook
        Set TargetSummSheet = Application.InputBox(prompt:="Select source sheet (select any cell)", Title:="Source sheet", Default:="A1", Type:=8)
        With HistoryTool.Sheets("Import Cost Helper")
            For i = LBound(cls) To UBound(cls)
                .Range("B7").Offset(, i).Value = TargetSummSheet.Parent.Range(cls(i)).Value 'may have to adjust CWB sheet ref
            Next i
            .Range("B7:AD7").EntireColumn.AutoFit
        End With
        CWB.Close False
    End If
End With

End Sub