First of all, since it’s a memorial, you have the option of using either the Weekday antiphon or the Common antiphon.Since tomorrow is a Memorial, would it not be
“Come, let us worship God, wonderful in his saints (alleluia)”
or
“Let us sing praise to God, as we acclaim Saints Joachim and Ann (alleluia)”
?
One thing I haven’t been able to work out is when the alleluias here are said. My guess is that it is on Solemnities, not Memorials or Feast days, nor ever during Lent. (What about Sundays?) Maybe somebody knows the answer?
If you opt for the commons, there are two. You can say either antiphon, since it’s an “or” thing.
The Alleluias after antiphons, if enclosed in parentheses, are said during the Easter season only.