Remembering "Yaaleh v'Yavo" before the end of the amidah

Hi,

We have mentioned that one who omits “Yaaleh v’Yavo” at shacharit or minchah on Rosh Chodesh must repeat the amidah. However, one who remembers “Yaaleh v’Yavo” before stepping out of the amidah should return to the beginning of “Retzeh,” say “Yaaleh v’Yavo” and go from there.

(Shulchan Aruch Orach Chaim 422:1)

Have a great day,
Mordechai