Q: dl at once many msgs from many groups?

I am using OE6 and  want to search through a handful of groups, and want to
be away from the computer while the downloading proceeds.

Q:    How do I indicate that I want all parts of a multi-part message to be
downloaded after I have finished searching (the entire group(s))?

Q:    Must I return to each group to dl the selected messages specific to
that group?