The odd status of "Baruch HaShem l'Olam" at maariv

Hi,

As part of the weekday maariv service in many communities outside of Israel, a special blessing which begins "Baruch HaShem l'Olam" precedes the amidah. The blessing is composed of a series of biblical verses, followed by a paragraph which is a blessing. Are the opening verses considered part of the blessing, or are they independent? One practical distinction is in a situation in which one is reciting the verses and then one hears someone recite a blessing; if they are independent verses, then one may answer 'Amen' between the verses. If they are part of the blessing, one may not answer 'Amen'.

Per Rivivot Ephraim 1:175:2, the verses are viewed only as verses, and therefore one may answer 'Amen' between the verses.

Have a great day,
Mordechai