trying to insert file name as part of subject line of an email type of URL . . .

[lbrtchx]

in order to protocol an embedded email you go: Ctrl-K . . ., and in order to insert the name of the file in a document’s text you go: Insert > Field > More Fields . . ., but how do you insert the name of the file on the subject line of an embedded email, so that when a user clicks on it the filename is included in the subject?

[LeroyG]

Don’t found for Writer (LibreOffice 6.3.6.2 (x86)).

In Calc: =HYPERLINK(CONCATENATE("mailto:recipient@mail?subject=";REGEX(CELL("filename");"[^/]+(?='#\$)")))

With the help of @mariosv.