&! for bg

[meino.cramer@xxxxxx]

Hi,

when doing 

    <command> &!

the command?job goes into background and
is detached from the terminal so closing 
the shell/terminal will not stop the job.

But...
If the command is already running on a terminal
one can do a ^Z and bg to put it in the background
but closing the shell/terminal will stopping
the the job.

Is there something like bg! to put a running
job like &! ???

Best regards,
mcc