I believe "Mecherfeen" is Darija Arabic from Morocco. Probably elsewhere in North Africa like in Algeria, or Tunisia people have a different way of saying
"Nice to meet you". Well I think it's best to learn the most common colloquial terms when speaking with native speakers of Arabic.
For example it's very common to say " Tasharafna" or simply "Tasharaft".
In the Levant like in Lebanon some people might say " Tasharafna bi m3reftak"
"It's a honor to get to know you".
In Egypt they say " ForSa sa3ida فرصة سعيدة " which literally means
" Happy chance" like saying it's great opportunity to meet you and as a response you say " ana l-as3ad أنا الأسعد " it means " I'm happier" like saying I'm more happy to meet you.
But just to be safe, I think " Tasharafna " is the most common way to say
" Nice to meet you" through out the Arab world.