If using OOM is still an option, you can use Application.Session.GetSharedDefaultFolder to retrieve the default Tasks folder of another Exchange user. You can then create a new task there using MAPIFolder.Items.Add.
If using OOM is still an option, you can use Application.Session.GetSharedDefaultFolder to retrieve the default Tasks folder of another Exchange user. You can then create a new task there using MAPIFolder.Items.Add.