1. Cover corn husks with hot tap water in a shallow baking dish.
2. Bring chicken broth, creamed corn and milk just to a boil in a small saucepan over medium heat. Gradually add broth mixture to masa harina in a medium bowl, stirring with a wooden spoon, until well blended; cool.
3. Heat broiler. Line a broiler pan with foil. Arrange poblanos and bell pepper on prepared pan and broil 4 inches from heat 10 to 15 minutes, turning until skins are evenly charred. Wrap in foil and let stand 15 minutes. Peel, seed and dice chile and bell pepper; transfer to a medium bowl.
4. Heat oil in a large skillet over medium-high heat. Add onions and cook 2 to 3 minutes. Add garlic, reduce heat to medium and cook 1 minute more. Cool, then combine with chile, bell pepper and uncooked shrimp.
5. Beat lard, baking powder, salt and sugar together in a large mixer bowl, until smooth. Gradually beat in masa harina mixture by spoonfuls, beating well after each addition. Continue to beat 5 to 8 minutes more, until mixture is light and fluffy. Stir in shrimp mixture and cheese (mixture will be stiff).
6. Drain and rinse corn husks; keep covered with a damp towel (or follow foil directions below). Flatten one husk on work surface (overlapping two husks if small). Spoon 1/4 cup filling in center of husk. Spread into a 3-inch long log. Roll up lengthwise. Secure each end with string. Repeat with remaining husks and filling.To prepare tamales with foil::
7. Cut each foil piece in half to make two 6x9-inch rectangles. Spread 1/4 cup filling in center of each rectangle. Fold all sides in to form 2x3-1/2-inch packets. (Can be made ahead. Place tamales in resealable plastic storage bags and freeze up to 1 month.)
8. Place steamer rack in Dutch oven over 1 inch of water. Arrange tamales (unthawed if frozen) in rack. Cover; bring to a boil. Reduce heat to low and steam 30 minutes. Serve with Guacamole, if desired.