Separate dynamics from notes

[Gianmaria Lari]

First question
Suppose I wrote this score:

\version "2.25.2"
rh = \fixed c' {c4\pp d\p e\f f\ff}

\score {
  \new Staff \rh
}


Is there any "automatic" way to extract the dynamics in the score (maybe
assigning it to a variable)?
At the end I would like to easily transform the previous code in the
following one:

\version "2.25.2"
rh = \fixed c' {c4 d e f}
dy = {s4\pp s4\p s4\f s4\ff}
\score {
  <<
    \new Staff \rh
    \new Dynamics \dy
  >>
}


Second question
Sometimes I copy a long score without the dynamic and add them separately
later. For this operation I need to establish the dynamic location in the
score counting and adding the notes length. This is tedious and error
prone. Is there any way to make it?

Thanks,
Gianmaria