Correct save path and syntax to save workbookdirectly into ONEDRIVE subfolder

Hi everyone, some words of wisdom please....

I have a workbook with several sheets and macros. Some of these macros attempt to save/open files to/from a subfolder inside a local ONEDRIVE folder.
I need to be able to set this up on multiple machines (all with different OneDrive accounts)and for them all to work.....

When I test the following on a 'dummy' onedrive folder (that is not actually connected to OneDrive) this path/address it works.

Trying it on a 'real live' onedrive folder gives me an error.

Sub SaveWorkbookAsSchoolAndTeacherCode()
Dim NewName As String
Application.DisplayAlerts = False
FilePath = Environ("USERPROFILE") & "\OneDrive\!Registers"
NewName = "\HMS Register 2015-6 - " & Worksheets("Register").Range("G5").Value & " - " & Worksheets("Register").Range("G2").Value & ".xlsm"
ActiveWorkbook.SaveAs FileName:=FilePath & NewName
ThisWorkbook.Saved = True
Application.Quit
End Sub

I have also tried this with no sucess

Sub SaveWorkbookAsSchoolAndTeacherCode()
Dim NewName As String
Application.DisplayAlerts = False
FilePath = "c:\User\\OneDrive\!Registers"
NewName = "\HMS Register 2015-6 - " & Worksheets("Register").Range("G5").Value & " - " & Worksheets("Register").Range("G2").Value & ".xlsm"
ActiveWorkbook.SaveAs FileName:=FilePath & NewName
ThisWorkbook.Saved = True
Application.Quit

End Sub

and this is broken too .... ;(

Sub SaveWorkbookAsTempRegisterToMergeReportsForm()
    Application.DisplayAlerts = False
    Dim ExcelSaveAsName As String
    ExcelSaveAsName = Environ("USERPROFILE") & "\OneDrive\!Reports\hidden\TempRegisterToMergeReportsForm.xlsm"
    ActiveWorkbook.Save
End Sub

Please can anyone help?

Many thanks in advance :

Gideon