How can I work this?
{dlgchoose|Choose an option|Option1={dlgchoose|abcd|word1+word2}+manualoption={dlgstring|Insert a word}}
It seems that is doesn't work, but why?
You can't nest dialog choices inside each other. (And even if you could, Opus would evaluate them in the wrong order, asking you for the inner ones before the outer one.)
Thanks for answer, but then, how can i do a button that "emulate" the action of a dialog inside each other?
How do you plan to run the result? If from a toolbar or menu, you're better off making a menu that has the different options as separate menu items. Then you can simply select from a menu instead of using a drop-down.