Movie data from one field to another

hi,

i am using microsoft access 2007 and i am trying to move some data from one field to another one. the data look like this “12345-6789” where “12345” is the zip code with a “-” in between and “6789” is the zip+4 code.

what i am trying to do is to move everyting that is after “-“. how i could tell access to perform such a task?

thank you in advance.