My dear expert modders, i am stuck with a stupid problem, i hope you can help me. Here the situation: i have a mod A with - for example - a nice item, and a mod B that modifies the vanilla perks, my aim is to create a new mod that will use the item of the mod A and, at the same time, has a perk that trigger a special effect with this item.
I've tried different ways but i can't find the solution, to semplify the question: imagine that i want to create a new mod based on an old one, but i dont want to overwrite it, how can i do it? I have tried to esmify the old one with wrye bash, then to load it in the creation kit, then i have saved the new esp (based on the old mod), and now? what i have to load? the old mod as esm and the new esp? or the the old mod as esp and the new esp? or what?
Sorry if the question has already an answer but i didnt found one helpful
And sorry for my bad english
My thanks!

You need to load the old mod as a esm and the new one as a esp. Anyway, keep in mind that there are various tools on the way that could allow to do this without needing to esmify the first mod.

Unless I misunderstand the OP question, if you want to keep the old mod as well as using the new mod that references the old one, surely you can simply load both esps, and set the new one as "Active".

I have one mod which has armours (my mod "A") and a house mod (mod "B"). I wanted to place some of the armours from "A" into my house mod "B" so all I did was, in the Data list, to check both esp files, and set mod "B" as the "active" one. That loads the data from both mods, but will only save to the "active" mod. Providing you will always keep mod "A" in your load list (and make sure mod "B" is after mod "A" in your load order), your mod "B" should always have references to mod "A" intact.

Does this make sense?

You don't need to "link" the two together.

You can just use http://www.creationkit.com/GetFormFromFile_-_Game in ModB to get at the relevant forms (objects) in ModA

(assuming a player has BOTH mods loaded when they play a game)