Hi Mario,
Thanks for using Syncfusion products and for your patience.
Currently we don’t provide the support for applying the template marker for above said scenario. We have logged the feature request and send to the development for further analysis. As you have created the new incident (id:95105), we will update you further details in this incident on 6/6/2012.
Please let us know if you have any concerns.
Thanks,
Manikandan.M