How can I open file in exist window?

I'd like that starting XEmacs-NT [version 21.4; April 2001] as

xemacs +100 foo.tex

should open foo.txt at line 100 with launched instance of XEmacs,
rather than start another one.

The program `winclient.exe' does not meet my needs, becase it does not
recognize the option `+number-line'.