Case endings to pronouns (Quenya)

Is it possible to add case endings to pronouns, as if they were nouns? Could I say for instance: "Nye ménan lyello" (I come from you)? Or are just the nominative cases of the pronouns allowed? At least I read that lyenna exists. So is also everything else possible, like lye, lyē, lyello, lyeo, lyenna, lyen, lyesse, lyes, lyenen, lyeva and lyeve, and also nye, nyē, nyello, nyeo and all the rest of it?

You can add case endings to pronouns. It is attested.

nai elen siluva lyenna
may a star shine upon you

If you want to express "I have come from you," you use perfective (men- > eménie-) with pronominal -n:

eménien lyello.
I have come from you.

Regards, Leonard

Thanks

So ... are the dative and possessive pronouns still necessary? Why should one use words like nin, ven and men if it's possible to say inyeo, elveo and elmeo instead? Would there be any differences?