How to add entries to an org file, not diary

[Stephen Eglen <S.J.Eglen@damtp.cam.ac.uk>]

Dear all,
If I'm visting an agenda (C-c a a) buffer, and want to add a diary entry
for a particular day, I can use org-agenda-diary-entry, bound to 'i'.
This inserts an entry in my diary file.  

What I'd like to do is add the entry instead to an org file,
e.g. 'agenda.org' where I currently store all diary-like entries.  Is
that functionality available?  (Am trying to wean myself off diary
files, after many years of using it...)

Thanks, Stephen