Could not find a part of the path - error when attempting to write a file to a shared drive

Experts,  I see quite a bit has been written on this.. and I even saw what appeared to be a perfect post on the internet for my problem.. but it did not resolve it.....

problem:
in a web .net environment.. vb.net  I am writing a file to a directory specified by the user... if the directory exists on the web server... then no problem the file can be written..

but if the directory is a shared drive (shared on the server.. NOT a the users share)  we get the error "could not find a part of the path".

There is a good article on the interrnet about how remote server doesn't know the user.... so we did the following
1) found the web user  "iusr_california"  on the web server
2) added that user on the remote machine
3) added that user to permissions on the shared directory.. gave the user full access
4) even made sure the password for the user on both machines was the same.
5)  then we used the path:   111.11.11.1111\sharedrivename\  as the write to directory..

now we get the error  access denied....  even allowed "everyone" access to directory on the remote server and still results in access denied when we try to write to the directory on the shared drive.

 this server (server 2005)  operating system server 2003.... using vs 2005....

I saw a lengthy article about a similar problem when running a service.. but that is not our environment.

this is a gui web application where user gets to pick the location he writes file to...

I am beginning to think it would be easier to write a simple batch program that moves the files from the web server to the target server.. since this does not change very often for the customer

thanks.