Just quote and delete the other lines that you don't use...
or
Select the lines that you want to quote, click on the right mousebutton and copie, and then click on reply and there in the lines above the message you see a piece of paper and if you click on tehre you have a quote tag, click in between and paste the lines that you have copied between the quote tags.
If you do this then it won't say quote from the person you have quoted....