Change wording in appointments

Hi
Everything is working fine but wondered if it was possible to change the wording in dashboard for appointments. There is a dropdown box when editing each appointment which has the titles confirmed, reservation, pending, abandoned and cancelled I would like to change these to confirmed, match, competition, surreys and cancelled. I know these words appear elsewhere but I only need to change them in the appointments dropdown box. I was hoping it may be just changing something in one of the language files and if so what file would it be.

Thanks

Steve