I have the following code:

\showframe
\setuplayout[topdistance=0mm,topspace=10mm,header=10mm,headerdistance=10mm,
            footerdistance=5mm,footer=20mm,bottomspace=2mm,
            backspace=25mm,
            
rightmargin=10mm,rightmargindistance=1mm,rightedge=0mm,rightedgedistance=0mm,
             
leftmargin=15mm,leftmargindistance=1mm,leftedge=9mm,leftedgedistance=0mm,
            width=fit,height=fit,
             location=middle]

\newdimen\RightMarginWidth \RightMarginWidth=\rightmarginwidth
\def\PageNumber#1{\vbox to \footerheight{\vss\hbox 
to\RightMarginWidth{\hss #1 \hss}\vss}}
\setuppagenumbering[location={margin},alternative=doublesided,command={\PageNumber}]

\newbox\ContinueNextPage \setbox\ContinueNextPage=\vbox{\strut\hbox 
to\textwidth{\hfill\mathematics{\blacktriangleright}\mathematics{\blacktriangleright}\quad}}


\starttext
\dorecurse{20}%
{\framed[width=\textwidth,height=3em,align={middle,lohi}]{\hfil
    \CONTEXT --\recurselevel \hfil}}%

\stoptext


I would like to put \copy\ContinueNextPage after the last \framed in 
every page
(in this example, after CONTEXT--18 at page 1 and CONTEXT--36 at page 2).

I don't want use tables/tabular, i try to use \vsplit.

I try to read page-ini, i find useful things like \everyafterpagebody
but i'm still confused.

Thanks in advance,
luigi