Change Focus Between Applications

I am using MS Word to create a list to go into Excel, it seems advantageous to do it this way because I'm using the Heading Outline Numbering feature of Word.

Presently my macro assumes the word document is closed. How do I modify the macro to:

1. check if the file is open?
2. if already open, switch the focus to word?
3. switch the focus back to excel?

Sub GetDataFromWordDoc()

Dim FileToOpen As String

FileToOpen = ThisWorkbook.Path & "5Whys.doc"
Sheets("Data1").Select
' MsgBox "Active sheet is " & ActiveSheet. Name ' My check
ActiveSheet.Range("WordClear").Select ' Existing data to remove
Selection.Clear

Set appWD = CreateObject("Word.Application")

' here I would like to check if the word file is open

appWD.Documents.Open Filename:=FileToOpen '

appWD.Visible = True
appWD.Selection.WholeStory
appWD.Selection.Copy

Range("WTarget").Select ' Single cell range to start paste
ActiveSheet.PasteSpecial Format:="Text", Link:=False, DisplayAsIcon:= _
False
'Range("D3").Select
'ActiveSheet.Protect DrawingObjects:=True, Contents:=True, Scenarios:=True
Sheets("5_Why_O").Select

' At this point word in the fore, excel in the back,

End Sub