The part of your question
I'm trying to develop a sub routine where I need to copy the next word whenever appears "Modelo:", example:

Modelo: OPTIFLUX 2100 C
The text I need to copy is "OPTIFLUX 2100 C", there is a tab between "Modelo:" and "OPTIFLUX 2100 C".
is fairly straightforward. The rest of your question is incomprehensible.
For a start you have asked for the next 'word' after "Modelo:" and yet your example has three words and there is no context in relation to what else is in the document or how it is formatted?
How for example would a macro know when the required string ended? The next word would be OPTIFLUX which is easy, but how is the macro to know that you want 2100 or 2100 C also?

You have a list of things to exclude, but what do you want to do with those words that are not excluded when they are found?