multiple kill and paste from X clipboard

[Manuel Giraud]

Hi,

I'd like to be able to paste a serie of strings from Emacs to an
external X program (e.g. a form with multiple entry in a web browser).

I could put all the strings in the Emacs' kill-ring but then a paste in
the other program will just retrieve the last killed string.  Or maybe,
Emacs could be informed that the last kill was paste externally and then
proceed to kill the next item?

How could I do that?
-- 
Manuel Giraud