Change FormatString on sharpdevelop Reports

Hi everyone

I need to get the date separated on 3 BaseTextIten's but on a format that doesn't apeer on the FormatString.

I need to get the date like:

txtDay - "21"

txtMonth - "May"

txtYeat - "2014"

Is there any way to add new FormatStrings to the SormatString field?

Thanks