Keep Formatting during Copy and Paste in Text Box

Hi everyone,

I'm using Adobe Acrobat XI v11.0.0 on Windows 7.

When I am copying and pasting numbers and text within the same text box, I lose the original formatting. How can I paste with the formatting retained? For example, if I copy Bold1234subscript , pasting within the same text box gives me Bold1234Subscript.

However, formatting is preserved when I copy and paste the entire text box.

Thank you very much!