I have a C# .net dll script that calls a SQL stored procedure that SELECTs data in order to do run relevant methods.
SELECT
I need to run the dll using PHP as
Using COM directly has many caveats and issues.
There is a library called NetPhp that abstracts on top of COM using reflection, so that you can call ANY .dll from within PHP without hassle:
http://www.drupalonwindows.com/en/blog/calling-net-framework-and-net-assemblies-php