Custom "Create Subfolder(s)" name?

In Bridge when using the Get Photos from Camera function I would like to have Bridge create a subfolder using the Shot Data but I want it to add a hyphen to the date between year and month and again between month and day. The existing option of "Shot Date (yyyymmdd) is almost perfect, I just want to make it yyyy-mm-dd. Is it possible to add this to the drop-down or to use the custom entry and use some sort of variables to make this work?