how to get message using extended mapi

If i have a mail path like
file://./backofficestorage/red.local/MBX/user1/inbox/mail1.eml

Then how to access access this message using extended mapi

I am successfully login to the user (user1)
Mapilogonex(userprofile);

Please give any sample

i think through message path we cant access that message suing extended

i think through message path we cant access that message suing extended mapi

but if i have message entry id then we can access that message.
but when i try to get its message store i get following error
0x80040111 ClassFactory cannot supply requested class

how to remove this error and get message successfully