Cook pasta according to package directions; drain.
Return pasta to saucepan.
Meanwhile, in a large skillet cook asparagus, squash, and garlic in hot margarine for 2 to 3 minutes or until vegetables are crisp-tender, stirring frequently.
Remove with a slotted spoon and add to pasta.
Combine whipping cream and lemon peel in skillet.
Bring to boiling.
Boil for 2 to 3 minutes or until mixture is reduced to 1/3 cup.
To serve, pour cream mixture over pasta mixture; toss gently to coat.