Why not think about it the other way?

Instead of having mirc set away when you change your nick, why not change your nick when you set away? That seems simpler. Type this once:

/alias /goaway nick russ|AWAY | away Gone for the day }

And then type /goaway whenever you want to set away

- argv[0] on EFnet #mIRC
- "Life is a pointer to an integer without a cast"