# Refer to complex note-like citations

I have recently asked this question about complex note like citations:

There, I was looking for a way to implement comments into my references, in order to obtain the typical bibliography used in chemistry journals:

I like the solution provided by Joseph Wright, which uses notes2bib plus the \fullcite command along with adjustion that references referred to by \fullcite are not additionally included in the bibliography. However, I am missing the option to refer to the individual entries of the bibnote. Is there a way to add a letter to the bibnote number when referring to an entry in the way: [1a], [1b] ... For example by using something like \bibnotemark[note1][a] to produce [1a] and \bibnotemark[note1][b] for [1b] etc.

Here's the MWE from the Question mentioned above:

\documentclass{article}
\usepackage{csquotes}
\usepackage[backend=biber,style=chem-acs,mcite,subentry]{biblatex}
\usepackage{notes2bib}
\bibnotesetup{cite-function = \supercite} % Make notes use superscript citations
\usepackage[utf8]{inputenc}
\bibliography{\jobname}
\DeclareBibliographyCategory{complexcited}
\newcommand*{\complexcite}[1]{%
\fullcite{#1}%
\addtocategory{complexcited}{#1}%
}
\begin{document}

For complex notes, things need to be done by
hand.\bibnote[note1]{This type of thing is described in:
a) \complexcite{Grubbs2003a},
b) \complexcite{Herrmann1999},
c) \complexcite{Nolan2011}.}

\printbibliography[notcategory=complexcited]

\end{document}