How to Copy and Paste a Selected Portion of Text?

I have an Excel sheet which includes many large blocks of text. I'd like to create a macro that allows users to copy a selected portion of text, and paste (append) that selected text into a specific column (in the same row as the selection). For example, suppose cells C6, D6, and E6 contain large blocks of text. I want to manually select a portion of that text (let's say 5 or 6 words within cell D6), and then click a macro button (or use a shortcut key) to automatically copy and paste that selected text into cell $J6.

I'm not sure how the Selection property will work. If I manually select a portion of the text in cell D6, will Selection.Copy copy only the selected text, or all of the text in that cell? And if (as I'm hoping) Selection refers to the text, then how can I also (at the same time) figure out which row I'm working with? Will Selection.Row still give me the row number, if Selection is referring to the text and not to the range?

On a related note, what will Selection.TypeName be, if a portion of text is selected? I know TypeName = "Range" if a cell is selected. Will TypeName = "String" if text is selected?