title: Compile error: Constant expression required
body: <p>I've stumbled upon a compile error, but don't get what can be of the issue. When trying to chagne the symbol to an input variable ( TickerID ) I get the error, works perfectly fine otherwise when inputting e.g "yhoo" for the yahoo ticker name. </p>
  
  <p>Code</p>
  
  <pre><code>Private Sub CmdBtn_Add_Click()
  '---------------------------------------------------------------------------------------'
  ' Checks that inputted ticker name is correct and calls import class after confirmation
  '---------------------------------------------------------------------------------------'
  
  ' General Variables---------'
    Dim TickerID As String: TickerID = UCase(Add_Instrument.TxtBox_Instrument.Value)
  '--------------------------'
  
      'Check if input field is not empty
      If TickerID = "" Or Application.WorksheetFunction.IsText(TickerID) = False Then
          MsgBox "Please provide a valid ticker ID"
          Exit Sub
      End If
  
      Debug.Print TickerID
  
      'Check Ticker name exists through YQLBuilder class
      Dim YQLBuilder As YQLBuilder: Set YQLBuilder = New YQLBuilder
      Call YQLBuilder.TickerCheck(TickerID)
  
  
  '        Call ImportData(TickerID)
  
  '        MsgBox "Please check the ticker name. It is in the wrong format"
  
  End Sub
  Public Sub TickerCheck(TickerID As String)
  '---------------------------------------------------------------------------------------'
  ' Built 2014-11-05 Allows parsing of XML data through YAHOO API YQL
  ' 2014-12-21: Not fully built yet, see where it can be of use
  '---------------------------------------------------------------------------------------'
  
  ' General Variables---------'
  Const ConnStringStart As String = "http://query.yahooapis.com/v1/public/yql?q="
  Const ConnStringLast As String = "&amp;diagnostics=true&amp;env=store://datatables.org/alltableswithkeys"
  '---------------------------'
  
  
   Const ConnStringInput As String = "select * from yahoo.finance.stocks where symbol='" _
   &amp; TickerID &amp; "'" **&lt;----- Error here!**
  
      Debug.Print ConnStringStart &amp; ConnStringInput &amp; ConnStringLast
  
      Dim YQLNodes As MSXML2.IXMLDOMNodeList
      Dim YQLReq As MSXML2.DOMDocument60
  
      Set YQLReq = New MSXML2.DOMDocument60
  
          YQLReq.async = False
          YQLReq.Load ConnStringStart &amp; ConnStringInput &amp; ConnStringLast
  
      YQLReq.setProperty "SelectionNamespaces", "xmlns:f='http://www.yahooapis.com/v1/base.rng'"
      Set YQLNodes = YQLReq.SelectNodes("//CompanyName")
  
      Dim xNode As MSXML2.IXMLDOMNode
  
      For Each xNode In YQLNodes
  
          Debug.Print xNode.Text
  
      Next xNode
  
       Debug.Print YQLNodes.Length
  
  End Sub
  </code></pre>