question: how to create a new shell window from a shell

[sharethewisdom]

I'm aware that this isn't a Q&A site, sorry!

But please consider this zsh function:

xless() {
  { exec {stdin}<&0 {stderr}>&2
    exec urxvt -e sh -c "less ${(j: :)${(qq)@}} </dev/fd/$stdin 2>/dev/fd/$stderr"
  } &!
}

This is useful for collecting stderr or grepping verbose output that would otherwise go off screen. Now, by piping something into xless, I want a new shell window to (remain) open within dvtm instead. (not running X) How would you go about doing that? Any advice would be welcome.