This ability came to tcsh at version 17.01, so my tcsh: propmt> tcsh --version tcsh 6.17.00 (Astron) 2009-07-10 (x86_64-unknown-linux) options wide,nls,dl,al,kan,sm,rh,color,filec
Does not allow this, but the very next version would support it.
https://github.com/tcsh-org/tcsh/compare/TCSH6_17_00...TCSH6_17_01 <- look under "Files changed" tab and look toward the bottom for line 5019 of the tcsh.man file.