User Avatar from another program

[iamspookysdaddy]

I user VB4 CMS with a integrated register/login from another program. This program has a profile that allows user to upload an photo for avatar. I wish if user uploads a photo that this photo will become the photo that displays for user in vbulletin.


This code is allow this type of image swap for punbb forum.
]$user_avatar = '<img src="http://www.yoursite.com/viewthumb.php?user='.$cur_post['username'].'" />';

I need assistance to learn how to proceed. If anyone can perform this I certainly will pay for service. I will post in paid service but for now want to get some direction if this is possible to do.

Thanks!