Accessing Service Programs from .NET

I have not found much so far to help with this in the archives or the
manuals.  

We have agreed to have another company manage our web presence using a
package that company has developed.  The other company uses .NET (C#) over
SQL Server as its development environment.

These programs need to be able to execute procedures we have embedded in
service programs on our iSeries (V5R2) to retrieve different information
stored on our iSeries so we won't have business logic stored in more than
one place.  Stored procedures apparently only work with an OPM model and
user defined functions must apparently be used in a "Select" statement.

Communication via sockets is potentially an option and I do have Scott
Klement's excellent sockets tutorial.

If it matters, communication with our iSeries will be over a point to point
T1 line from a remote site.

I would greatly appreciate any advice, samples, or RTFM pointers.

Thank you. 

Donald R. Fisher, III
Project Manager
Roomstore Furniture Company
(804) 784-7600 extension 2124
DFisher@xxxxxxxxxxxxx