Populate blank cells based on column values from multiple sheets, using Item Number and column headers

[SkywardPalm]

I'm attempting to pull blank column data from multiple sheets based on the cell value in a column named "NDC." I want the macro to be universal so that if I call it on a sheet that has the "NDC" column, it will pull data into all blank cells based on the NDC column's cell value. It's intended to keep certain libraries filled with relevant data from any referenced source that shares column headers, but could be used in any situation applicable.
I have the VBA code written within a UserForm in which the User selects the sheets to reference...

Option Explicit
Private wbReference As Workbook

Private Sub butCancel_Click()
    Unload Me
End Sub

Private Sub butOK_Click()
    'Me.Tag = "OK"
    Me.Hide
    PullData Me.Items

End Sub

Private Sub UserForm_Initialize()
    Dim sh As Worksheet
    Dim ReferenceFileToOpen As Variant
    'Me.ListBox1.Clear
    ReferenceFileToOpen = Application.GetOpenFilename(Title:="Browse for Reference Excel File", FileFilter:=" Excel Files(*.xls*),*xls*")
    If ReferenceFileToOpen <> False Then
        Set wbReference = Application.Workbooks.Open(ReferenceFileToOpen)
        Dim n As Long
        For n = 1 To wbReference.Sheets.Count
            ListBox1.AddItem wbReference.Sheets(n).Name
        Next n
    End If
End Sub

Public Property Get Items() As String()
    Dim i As Long, selected As Long
    Dim selectedItems() As String
    
    For i = 0 To ListBox1.ListCount - 1
        If ListBox1.selected(i) = True Then
            ReDim Preserve selectedItems(selected)
            selectedItems(selected) = ListBox1.List(i)
            selected = selected + 1
        End If
    Next i
    
    Items = selectedItems
End Property

Sub PullData(ArrayItems() As String)
    Dim x As Integer
    Dim rReferenceColHeaders    As Range
    Dim rActiveColHeaders       As Range
    Dim rColHead                As Range                ' Iterates through the Reference column headers
    Dim rMatchColHead           As Range                ' Gets the matching column header
    Dim iNumCellsPerColumn      As Long                 ' Defines how many cells per column we're copying
    
    Set rActiveColHeaders = ThisWorkbook.ActiveSheet.Range("A1:AZ1")

    'loop from the lower bound of the array to the upper bound of the array - the entire array
    For x = LBound(ArrayItems) To UBound(ArrayItems)

        Set rReferenceColHeaders = wbReference.Sheets(x).Range("A1:AZ1")
    
        ' set number of cells to reference per column/sheet
        With wbReference.Sheets(x)
            iNumCellsPerColumn = .Cells(.Rows.Count, "A").End(xlUp).Row
        End With
    
        ' process
           '==========================================
           ' - loop through the Reference column header cells
           ' -- try to find the matching column
           ' -- if a match is found, set blank cell values to xlookup from NDC column and highlight found data
        For Each rColHead In rReferenceColHeaders
            Set rMatchColHead = rActiveColHeaders.Find(rColHead.Text, , xlValues, xlWhole)
            If Not (rMatchColHead Is Nothing) Then
                'This is the part where I get confused
            Else
            Debug.Print rColHead & " Header Not Found"
            End If
        Next rColHead
    
    'create new sheet that displays changed rows with highlighted data
    
    Next x
End Sub

 

[SkywardPalm]

I found the solution to this and have moved onto another issue I am having here. Feel free to reference the code from this next post if it helps you.