Easy question working with strings

I have a Name field where I need to extract just the person's last name. I
did not originally set up the database as I would have separate fields for
first and last name, but this data is being pulled from an AS400 where it is
just one field.

I was thinking of something like trying to find the space in the name,
marking that location and then trimming the beginning of the string, but I
would have to start searching for the last space because the middle name
could be included.

So I have: Douglas Bell
Nancy E Basham

I want to extract just 'Bell' and 'Basham'.

Is there an easy way to go about this?

Thanks for the advice.

Brad