Yes, you can move information from Excel into Primavera 3.0
This is called the import/export feature by P3.
The easiest way to do this is
-- create a dummy file OUT of P3 (TOOLS/Project Utilities/EXPORT). This will create a DBF or WK1 type template for you to modify.
--Open EXCEL, then open the template file.
-- Copy/Paste information in, being careful not to change the titles or the column widths. Save the file dBase/DBF format
-- Bring the info back into P3 (TOOLS/Project Utilities/ IMPORT)
The Primavera CD-rom help file has more information on this topic.
