In Creo 2.0 it works like this. Sketch your shape in the drawing. When completed, select it and hold down the RMB - you should see Hatch/Fill in the popup menu. It will prompt you for a name for the cross-section and default to a hatch fill. The old Menu Manager will appear allowing you to change spacing, angle, from hatch to fill, etc...
I assume it does the same in Creo 1.0. I also see Hatch/Fill under the Sketch and Layout tabs in the Creo 2.0 ribbon menu - not sure about Creo 1.0
Mike Brattoli
Moen Incorporated
Global Product Development Process Management
Administrator - PLM
25300 Al Moen Drive
North Olmsted, OH 44070