Q. An ovel during shiva that doesn’t have a minyan at home and comes to Shul, when he davens for the amud, does he say Birchas Kohanim? Lam’natzeach and the parts of Uva Letzion that are omitted in the ovel’s home?

A. There is a disagreement between Poskim if you recite the Elokenu Velokey Avosenu that stands for Birkas Cohanim in the ovel’s home. Eliahu Rabbah (559: 13) quoting Shiurey Knesses Hagdolah, Chidushei R” Akiva Eiger (131) and others maintain that it is not said. Daggul Mervavah (ibid. 127), Chayei Adam (27: 25), Teshuvah Meahavah (1: 50) rule you do.
The generally accepted custom in most Diaspora communities is not to recite it on the mourner’s house during weekdays. (Mourning in Halacha 16: 25: 52)

It would stand to reason that according to Halichos Shlomo (Tefilah 11: 10) that when the ovel leads the services in shul you do not recite tachanun since the congregants follow him and the shul is considered as the ovels home, you would then also not recite Birkas Kohanim, Lam’natzeach and V’ani Zois Brissi (in Uva Letzion). However Horav Shlomo Miller’s Shlit’a opinion is that even when the ovel davens before the amud in shul, those parts normally omitted in the ovels’ home are recited by the attendants, the ovel though, omits them.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a