IPhone :: Transfer The Music To Itunes From It?

After having to re-boot my PC, I unfortunately lost some of the music on my iTunes account. The songs are still able to be played on my iPhone but in the iTunes account, to the left of the tick box there is an exclamation mark, and when I click on the song to play it, a box comes up telling me that "the song can not be used because the original file could not be found." Is there any way of me being able to get the songs from my iPhone back onto my iTunes account?