So what is your Empl object? If you have a multi-tiered system, what layer(s) use this object? You are right that Struts forms should us String values. If Empl is a business or data layer object, then I would probably create an ActionForm that had fname and dob fields as Strings. You would then have to write code that populated the form from the Empl object and populated an Empl object from the form. It is a little bit of a pain, but not too bad.
For read only pages (like search results pages) I have added methods like getFormattedDob() to data layer objects. In this case, iterating over a collection and translating each data object into a presentation object seems like too much overhead just to format a few fields.