Get document ID from word application

Ok, I found a way to get the ID, it is to use the FindObjectVersionAndProperties method from the MFilesClientApplication object. It uses the ThisDocument.FullName to get the current word / excel document's full path on M-files (ex. M:\VaultName\...\filename.docm) and returns the ObjectVersionAndProperties where you can get any info of that object further.

Here is the piece of code, you just need to change the name of the vault:

Function BindToVault() As MFilesAPI.vault

    ' Read the name of the vault to bind on client side.
    Dim szVaultName As String: szVaultName = "VaultName"
    
    ' Instantiate an object that represents the M-Files application.
    ' This is the base object that must be used to perform any other operations.
    ' Note: via this object we communicate with the M-Files Client software.
    Dim oMFAPIApp As MFilesAPI.MFilesClientApplication
    Set oMFAPIApp = CreateObject("MFilesAPI.MFilesClientApplication")
    
    ' Bind to given vault.
    Dim oVault As MFilesAPI.vault
    Set oVault = oMFAPIApp.BindToVault(szVaultName, 0, True, True)
    
    ' Return value.
    Set BindToVault = oVault
    
    
    ' Locate the object by path from M-Files.
    Dim oObjVerAndProp As MFilesAPI.ObjectVersionAndProperties
    Set oObjVerAndProp = oMFAPIApp.FindObjectVersionAndProperties(ThisDocument.FullName)
    
    ' Get the object version ID of the current document
    Dim objectVersionID As Long
    objectVersionID = oObjVerAndProp.ObjVer.ID

    MsgBox "The ObjectVersionID of the current document is: " & objectVersionID
    
    ' Release resources.
    Set oMFAPIApp = Nothing
    Set oVault = Nothing

End Function