Easy or even Possible? file I/O + user input

A challenge was posted on a forum I frequent, and
when trying to golf down my solution I came across
something of a conundrom.

The challenge is simple:
Take a filename and a word on the commandline
or stdin and print the number of occurences the word
has in the file.

Now, I don't want to use open() or @ARGV, because
that's bad form(?), ie long.

Well, my final solution, that isn't really a solution was:
-0ne '@a=/WORD/g;print int@a'

Now, this isn't really a solution because it has the WORD
hardcoded. But, how would I be able to get the WORD
when using -n? I'm guessing this isn't possible.

So, how would one get the 2 values from the command-line
or stdin without spending so much code on open() and ARGV?

Tor