Passing variables to cli curl

I have a script that uses cli curl, and it would be easier if it was possible to pass variables like this:

curl -c $cookie -d $data www.********.com

This doesn't work, instead I have to generate a string and use eval.

Is there another, easier way to pass variables to cli curl?

Not sure what you are asking? You have files that the www.*.com expands to generate no-prefix URLs?