Using the Runtime.exec() function, I have been able to communicate, to a degree,
with the windows ftp program but have problems when trying the same thing
with another program.

(incidentally, the 'other program' happens to be the same secure telnet application
I have mentioned in a previous question entitled "grab window contents (text)")

What alternatives are for starting an external program and communicating
with it (getting it's output, send it input)?