Missing Title and Artist tags in files

I have several hundred mp3 files that have no tags. The filename is in the format

artist - title.mp3 e.g. "Buddy Holly - Everyday.mp3"

Is there a way to take the artist part and copy it into the artist tag and the same with the
title.

Been trying to work it out for ages.

Convert > Filename - Tag

Yes, this. And I would like to add that if the OP is not really familiar with that function that he could try the following mask:

%artist% - %title%
There is a preview function that will help to predict the results.

I think you misunderstood. The filename is fine - I am trying to populate the artist and title
fields.

I already use the convert filename script - where I have artist and title.

I refer to
Convert > Filename - Tag
(as stanman already said)

BTW: Now you have got the hint twice that there is a converter to exchange data between tags and filenames and vice versa.
There is also an online help that explains this feature quite thoroughly.
Have a look at these sources of information to see where the misunderstanding might be.

Apologies. I was clearly over-complicating things. Must simpler than I expected.

Thank you for the help.