Path & sharepoint

I have an Excel project with VBA macros, where I create a subfolder with a certain name in the folder containing the project xlsm file (unless the subfolder already exists). Then, I produce a host of new files that I to save in my subfolder. I use omething like FSO.CreateFolder(ThisWorkbook.path + "" + NewFolderName), and it worked great, till my company switched to syncing my Documents folder with OneDrive. Now, ThisWorkbook.path returns a string like "https://hfc-my.sharepoint.com/personal/[username]_[domain]/Documents/..." instead of "C:\Users\[username]\Documents\...". Note the URL instead of a drive specification, and slashes instead of backslashes. How do I fix this (apart from moving my project to a folder unaffected by OneDrive)?

Actually, I have wrapped FSO.CreateFolder into this function (lifted from another forum post, and working wonderfully up until now):

Function MyCreateFolder(path As String, Optional FSO As Object) As Boolean
If FSO Is Nothing Then Set FSO = CreateObject("Scripting.FileSystemObject")

If FSO.FileExists(path) Then
MyCreateFolder = False

ElseIf FSO.FolderExists(path) Then
MyCreateFolder = True

ElseIf MyCreateFolder(FSO.GetParentFolderName(path), FSO) Then
If FSO.CreateFolder(path) Is Nothing Then
MyCreateFolder = False
Else
MyCreateFolder = True
End If

Else
MyCreateFolder = False
End If

End Function

My problem is, the FSO.FileExists(path) and FSO.FolderExists(path) never turn true for these sharepoint paths, though the FSO.GetParentFolderName(path) works well with these paths.