Not without a lot of extra design work. Portal Sort Orders are fixed. There are two work arounds that I know of:
1) Define a "sortkey" calculation field that returns the values of very different fields based on a value selected/entered into a global field or variable. This takes some extra work to get number, date and text fields to all sort correctly from the same calculation field.
2 ) Create several portals that are all identical except for the sort order. Put these portals on different layouts or different tabs of a tab control. "Sorting" the portal in a different order then happens via a button that changes layout or that selects a different tab in the tab control.