Hi Peg,
the sentence you have written:
'E a come è difficile vivere in un paese straniero' is not correct in Italian, as Ivana correctly said.
It would be correct if it is the continuing of a longer sentence, as for example: "Pensava alle difficoltà del viaggio e a come è difficile vivere in un paese straniero"... is this the case? If it is the case, the preposition 'a' is referred to a verb, in this case to the verb 'pensare', as we say 'pensare A qualcosa'.
Ciao ^_^