When doing idghaamu-l-meemi-l-saakinah in between the Laam and Meem in- Alif Laam+Meem, do you apply the same rule and count as you word for the ghunna in a regular idghaamu-l-meemi-l-saakinah ? jazaakallaah

Question
as-salaamu alaikum
when doing idghaamu-l-meemi-l-saakinah in between the Laam and Meem in- Alif Laam+Meem, do you apply the same rule and count as you word for the ghunna in a regular idghaamu-l-meemi-l-saakinah ?
jazaakallaah

Answer
Wa aliakum assalaam wa rahmatulllahi wa barakatuh,
Yes, it is the same rule.  There is a meem saakinah followed by a voweled meem, so there is idhgaam and the ghunnah is the longest of all the ghunan in time .  This is the only case when the idghaam occurs within one word for the meem saakinah. 

 Please see: http://www.abouttajweed.com/the-ghunnah-and-its-ranks/ranks-of-the-ghunnah.html
                       http://www.abouttajweed.com/the-meem-saakinah/the-meem-saakinah-rules-part-2-idghaam-mithlayn-sag.html