MS Excel 2010 VBA compile error

Experts,

I receive a compile error in the below VBA on the statement, “Const FULL_PATH As String = SSreportBuilder.xls.UserForm1.SSFileName”.  The code is an object in Excel trying to run an enclosed macro with a selected workbook. The Names include:
      Spreadsheet: SSReportBuilder.xls
      Form: UserForm1
                Text Box named – SSFileName

Please provide your assistance and thank you in advance.


Private Sub cmdOK_Click()
cmdOK.Enabled = False
Dim app                          As Application
Dim wbTarget                 As Workbook
Dim strReturnedValue   As String
Dim SSFileName             As String
Dim strArg                      As String


If Risk = -1 Then

'================================================
   'Supply/Change fullname
'================================================
Const FULL_PATH As String = SSreportBuilder.xls.UserForm1.SSFileName

'================================================
   'Set a reference to the new instance
'================================================
Set app = New Application

With app
.Visible = True
.WindowState = xlMinimized

'================================================
   'Open Workbook
'================================================
Set wbTarget = app.Workbooks.Open(SSFileName)

'================================================
    'Run selected macro
'================================================
    Application.Run "SSreportBuilder.xls!McrRisk"
       
'================================================
    'Close Workbook and Kill the instance
'================================================
    Workbooks(SSFileName).Close savechanges:=False
        wbTarget.Close False
        .Quit
        MsgBox "The Workbook has updated Formats"
End With
cmdOK.Enabled = False
Else
    MsgBox "Please select a Macro"
End If

End Sub