Command button macro

Your macro can be shortened to:

Sub CommandButton1_Click()

    Dim varBook As Variant
    Dim otherWb As Workbook
    
    varBook = Application.GetOpenFilename
    If varBook <> False Then
        Workbooks.OpenText Filename:=varBook
        Set otherWb = ActiveWorkbook
                
        'inserts values into designated cell
        ThisWorkbook.Worksheets(2).Cells(1, 1).Value = otherWb.ActiveSheet.Cells(1, 1).Value
        ThisWorkbook.Worksheets(2).Cells(1, 2).Value = otherWb.ActiveSheet.Cells(1, 2).Value
        ThisWorkbook.Worksheets(2).Cells(1, 3).Value = otherWb.ActiveSheet.Cells(1, 3).Value
        
        ThisWorkbook.Worksheets(2).Cells(6, 2).Value = otherWb.ActiveSheet.Cells(2, 2).Value
    End If
End Sub

No need to store the locations of the values in the other workbook that you are looking for. A couple things I'd ask you:

Are there multiple worksheets in the workbook that is selected? Your code does not deal with sheets, so the active sheet will be where data is taken from.

I hate to ask, but are you sure you are looking for the data in cells A1, B1, C1, and B2?