Need to checkout MS Project file from Excel VBA

Question

I have a VBA Excel macro that can open an MS Project file, and extract data.  It works fine when the MS Project file is on my hard drive or other location where no check out is required.  But often the MPP files I need to access are stored in SharePoint,
in document libraries, that have checkin/checkout enabled.  I am aware of the the way to do this for an Excel file, such as the following code snippet.
 ' Determine if workbook can be checked out.
 If Workbooks.CanCheckOut(Filename:=docCheckOut) = True Then
  Workbooks.CheckOut (Filename:=docCheckOut)
 Else
  MsgBox "You are unable to check out this document at this time."
 End If
I need to be able to do the same thing for MPP files.  Here is the code I have; however, I get a compile error on the CheckOut line, indicating "wrong number of arguments or invalid property assignment".  My research suggests that I should
get this compile error, as it only works on certain collections.  Even the line containing "CanCheckOut", while it does not give me a compile or run time error, it does not return the proper response.
 Dim mpApp As MSProject.Application
 Set mpApp = New MSProject.Application
 AppActivate "Project Professional"
 ' Determine if mpp file can be checked out.     
 If mpApp.CanCheckOut(mppFileToOpen) = True Then
  mpApp.CheckOut (mppFileToOpen)
     Else
         MsgBox "Unable to check out this document at this time."
    End If
Is there a way to checkout an MS Project file stored in SharePoint from within Excel VBA?  Thanks.
Ray

Answer 1

Rod,
Thanks very much.  This was, indeed, the solution.  Don't know how I could have missed this.  
I did run into some issues with ensuring proper object references, checking back in, and being able to handle files that may be on a laptop, SharePoint site with checkout requirements, or SharePoint site without checkout requirements.  Also faced an
issue checking back in; part of my macro opens the MPP file (that is checked out), acquires various pieces of data, then runs a macro in the MPP file that exports data to an excel spreadsheet.  After this macro runs (does a save-as using a map), check
in is no longer possible.  Fortunately, I could checkout the MPP file, open it, get all the required data elements, make a few changes to the MPP file, check it back in (but not close), then run the macro, then close without saving.  In the end,
it all works like a champ.  Thanks very  much for your advice.
Ray