Compile error: Expected end of statement

Sub big_v()
    Dim LastRow As Variant
    Dim Lastcolumn As Variant
    Dim count1 As Long
    Dim count2 As Long
    Dim count3 As Long
    count3 = 10
    LastRow = Range("C6").End(xlDown).Row
    LastRow = -1 * (LastRow)
    Lastcolumn = ThisWorkbook.Worksheets("Data Sheet").Cells(3, 5)
    Lastcolumn = -1 * (Lastcolumn + 10)
    count2 = -3
    For count1 = -7 To Lastcolumn Step -1
        .Cells(6, count3).Select
        ActiveCell.FormulaR1C1 = "=VLOOKUP(RC["count1"],Sheet1!C["count1"]:C["count2"],5,FALSE)"
        count3 = count3 + 1
        count2 = count2 - 1
    Next count1
        
End Sub

i want to put the counters in the [] brackets but i get a compile error expected end of stantement