It is possible to add a deeplink to the bpost eTracker by using your own customer reference. In case you use the bpost Shipping Manager, this is your order ID.
Customer Reference / Order Reference
Please bear in mind that other customers may also use a similar order numbering. So, should you wish to use this solution, then we suggest to use an appropriate order numbering logic to ensure unique values e.g. "MyCompany_2015043001", rather than "123".