> How can these be combined into one clip?
> ^!Replace < < AIH
> ^!Replace > > AIH
> ^!Replace " " AIH
They are one clip as they stand. I don't quite get the question.
Just "Add New Clip", give it a name, any name, copy those three lines,
and you're done.
N.B.1: I prefer the alternative sytax ^!Replace "a" >> "b" AIH for
N.B.2: You've written "H" to limit your clip to a selection. You might
want to make sure it won't run and not do any mischief when nothing is
selected. Just add
^!If ^$GetSelSize$<1 END
as a first line.