As a temporary solution, I created many functions that add different FvwmButtons with fixed page numbers on each page. For example, on page 00… *foofunc0 0: (1x1, Title "Page 0-0") , on page 0 1… *foofunc01: (1x1, Title "Page 0-1") , etc.
To come back to the same page where the buttons were launched, do not use GoToPage but StartsOnPage. This adds the buttons on different pages without leaving the launching page. For example…
Style Grid00* SkipMapping, StartsOnPage 0 0
Style Grid10* SkipMapping, StartsOnPage 1 0
Style Grid20* SkipMapping, StartsOnPage 2 0
The result is interesting when having the page number on each page similar to Gnome Extension “Workspace Indicator”.
There is a better solution, which uses the *foofunc: (Title "Page: $[page.nx], $[page.ny]" same as presented on this topic. Still waiting for a reply from the old topic.