Bring broth to a boil in a large saucepan over medium heat; cover and reduce heat to low. Keep warm.
Meanwhile, melt butter in a large Dutch oven over medium heat.
Add onion, and saut 5 minutes or until tender.
Add squash, and cook, stirring occasionally, 4 minutes.
Add rice, and cook 2 minutes. Stir in wine; cook 1 minute.
Bring to a boil over medium-high heat. Reduce heat to low; add 1/2 cup hot broth, stirring constantly, until liquid is absorbed. Repeat procedure with remaining broth, 1/2 cup at a time. (Total cooking time is about 20 minutes.) Stir in Parmesan cheese and cream. Season with salt and pepper to taste.