The short answer is no, as you cannot use the colon symbol in a Windows file/folder name. The following will use a period/full stop instead. It will work provided the folder is the only sub folder, or if that subfolder does not begin with 'MICHAEL_'. If you are sure there will only be one subfolder you can remove the name check.
Code:
Option Explicit
Sub Rename_Folder()
Dim oFSO As Object
Dim oFolder As Object
Dim oSubFolder As Object
Dim i As Integer
Dim strPath As String
Dim strSubFolderPath As String
Dim strSubFolderNewName As String
strPath = "D:\MIHAI\DOSARE\BAAR"
strSubFolderNewName = strPath & "\" & "MICHAEL_" & Format(Date, "dd.mm.yyyy_") & _
Format(Time, "HH.MM")
Set oFSO = CreateObject("Scripting.FileSystemObject")
Set oFolder = oFSO.GetFolder(strPath)
For Each oSubFolder In oFolder.SubFolders
If Not oSubFolder.Name Like "MICHAEL_*" Then 'Optional
strSubFolderPath = oSubFolder.Path
Name strSubFolderPath As strSubFolderNewName
Exit For
End If 'Optional
Next oSubFolder
lbl_Exit:
Set oFSO = Nothing
Set oFolder = Nothing
Set oSubFolder = Nothing
Exit Sub
End Sub