open Project Professional and the global template, go to Tools > Customise >
Enterprise Fields.
Go to the Project Fields ( if you want % complete on project, but this also
works with tasks), choose Number as a type and rename the first available
number to "Project % Complete" ( please note you cannot use % complete bacuse
this name is already used by Project)
Click the "fomular" button and on the new dialog window chose the "Field"
button. Choose "Number" and then "% Complete". Click OK and OK again.
This fomula will now add the % complete value in the custom field and you
can make this custom field visible to PA. This should do the trick
Hope this helps