"echo" escaping

From: Douglas Gregor (gregod_at_[hidden])
Date: 2003-03-29 11:29:21

I've just found out that escaping sequences for "echo" on Windows and on Unix 
are very different, so to be able to use echo for anything non-trivial we're 
going to need some sort of "escape" rule. For example, I need to output this 
line to a file:

<?xml version="1.0"?>

On Unix, the echo command-line looks like this:

echo "<?xml version=\"1.0\"?>" >> catalog.xml

On Windows, it has to look like this:

echo ^<?xml version=^"1.0^"^> >> catalog.xml

Can anyone give me a hint on implementing this in Jam? The regex MATCH seems 
to be of little use, unfortunately :(

Doug