Exclude files and directories via Linux's shell, except some of them.

exclude_files_except

find . ! -name one ! -name two -maxdepth 1 -type f -delete

gistfile1.txt

!		negates the next expresso
-name		specifies a filename
-maxdepth 1	will make find process the specified directory only (find per default traverses directories)
-type f		will process only files (and not for example directories)
-delete		will delete the files

You can then tune the conditions looking at the man page of find

keep in mind that the order of the elements of the expressions is significant (see the documentation)
test your command first by using -print instead of -delete

> find . ! -name u ! -name p -maxdepth 1 -type f -print