I want to pre-generate the cache for a mobile version of a website.

I tried this:
httrack <http://www.empiremediationservices.com/> -c1R2Kb1s0ap0r3F -F
"Mozilla/4.0 (compatible; MSIE 6.0; Windows CE; IEMobile 7.11" "HTTrack cache
builder" -*.jpg -*.css -*.js -*.png -*.gif -*.jpeg -*.ico

But I get this error:
Example: -F "my_user_agent/1.0"
* Option F needs to be followed by a blank space, and a user-agent name

Can you help me with the correct user agent text?