set variable according to some (other) variable

[Tommy Wareing]

I'm trying to work out whether I can create a single macro to toggle
index format between two values.

Currently, I've got two keys bound:

macro index "\Cw" ':set index_format="%4C %Z %{%b %d} %-15.15L (%4l) %s"^M' "View 
Lists"
macro index "\Ca" ':set index_format="%4C %Z %{%b %d} %-15.15F (%4l) %s"^M' "View 
Sender"


But is it possible to do this in one?

--
Tommy Wareing
Oxford Brookes University