You could, however, code stuff like
Code:
if software=="Reaper" then
-- do the Reaper code
elseif software=="Renoise" then
-- do the Renoise code
end
where the variable software somehow holds the programname it runs on.
Depending on how much of the software itself is represented in the API-functions of Reaper and Renoise, you can code, that may do the same. Reaper gives you access to much of the stuff; if Renoise gives you the same amount of access, you may have a chance.
However, as soon as one thing is missing from one of the two programs, you're stuck.
And don't expect wonders. Some of the concepts of Reaper probably work totally different in Renoise or aren't existing at all.
I suppose AutomationItems should exist only in Reaper, so programming it in Renoise should be impossible(I suppose. I don't know Renoise).