Is there substring function or something like that in BI publisher?

Have a requirement for check design each number of the date has to be fit into each indivual box exactly. In XML source code, Date is coming out as 2013-06-26 (YYYY-MM-DD), is there a way to separate them into each indivual numbers, in this case, separate it as 0, 6, 2, 6, 2, 0, 1, 3 and so I can format each number indivually? Thanks