DHCP-TOOL: remove a lease

Hi All !
I am looking for a Command Line Tool to delete a inactive DHCP-Lease on a WinNT Server.

Important:
not a reservation, only a lease without a reservation. A reservation e.g. I can remove with the dhcpcmd tool from the Winnt RK.

It’s very important for me.
It also can be a 3rd party tool.

Please inform me, if you know something.

Bye
Herby