Cant use mid function on collection

[Piller]

Option Explicit
Dim Player As Boolean
Dim Space As Integer
Dim Win As Boolean
Dim Square(0 To 2) As String
Dim Wins As New Collection
Dim i As Integer
Dim j As Integer
 
Private Sub Form_Load()
For i = 0 To 8
    B(i).Caption = ""
    B(i).Value = vbChecked
Next i
With Wins
    .Add "012"
    .Add "345"
    .Add "678"
    .Add "036"
    .Add "147"
    .Add "258"
    .Add "048"
    .Add "246"
End With
End Sub
 
Private Sub B_Click(Index As Integer)
With B(Index)
.Value = vbChecked
    If Win = False Then
        If .Caption = "" Then
            If Player = False Then
                .Caption = "X"
                Player = True
            ElseIf Player = True Then
                .Caption = "O"
                Player = False
            End If
        End If
        
        For j = 1 To 8
            For i = 1 To 3
                [B]Square(i - 1) = Mid(Wins(j), i, 1)[/B]
            Next i
            
            If B(Square(0)) = "X" And B(Square(1)) = "X" And B(Square(2)) = "X" Then
                Win = True
                MsgBox "Player X Won"
                Exit For
            ElseIf B(Square(0)) = "O" And B(Square(1)) = "O" And B(Square(2)) = "O" Then
                Win = True
                MsgBox "Player O Won"
                Exit For
            End If
        Next j
        
        For i = 0 To 8
            If B(i).Caption = "" Then
                Space = Space + 1
            End If
        Next i
        
        If Space = 0 Then
            Win = True
            MsgBox "Tie"
        End If
    End If
End With
End Sub

(B is a checkbox that im keeping checked)
This is a tic-tac-toe game, and instead of checked all the checkboxs to see if someone won, I decided to use a collection and parse out each integer and check that way. I keep getting a error on the bolded line though and im not sure why. The line looks fine for me and should produce the results Square(0) = 0, Square(1) = 1, and Square(2) = 2. Could anybody help me with this?