Looping a Cell Reference in a match function

I'm pretty new to VBA and was wondering why my formula doesnt work?

I'm trying to loop the cells Sheets("Summary").Cells(11 + X, 13) in my match function but it doesn't seem to work. Am I doing something wrong?

Sub Reset()

Dim X As Integer

For X = 0 To 19

Sheets("Summary").Cells(11 + X, 13).Select
Selection.Formula = "=INDEX(YMAX!$A:$W,MATCH(Summary!$J$4&"" ""&Summary!$J$5&""     ""&11,YMAX!$B:$B,0),MATCH(sheets("Summary").cells(11 + x,9),YMAX!$1:$1,0))"

Next X

End Sub

Solution

It looks like you have the following errors

&'s are in the wrong places (should be outside of the quotes when concatenating text, inside the quotes when concatenating cell references)
Variables (i.e. your reference to a cell on the "Summary" sheet) do not need to be in quotes when building a string in VBA
(not an error, per say) You don't need to do .Select as you can set the formula of the cell directly.

Update your code with the following

Sub Reset()

Dim X As Integer

For X = 0 To 19
    ' Broken up on several lines for clarity
    Sheets("Summary").Cells(11 + X, 13).Formula = 
        "=INDEX(YMAX!$A:$W,MATCH(Summary!$J$4" & " " & _
            "Summary!$J$5" & "    " & _
            "11,YMAX!$B:$B,0),MATCH(" & _
                Sheets("Summary").Cells(11 + X,9).Address & _
              ",YMAX!$1:$1,0))"

Next X

End Sub

I'm not sure if that's the formula you want exactly, but it's what i interpreted given your current code. Let me know if that works for you.