Microsoft KB Archive/42628
INF: Using Built-In Functions with Triggers ID Number: Q42628
1.10 1.11 4.20 OS/2
A trigger cannot execute C routines directly, but a trigger can call stored procedures as subroutines. In SQL Server version 4.2, a trigger can call a remote stored procedure; therefore, it is possible to execute a C routine as an RPC via Open Data Services (ODS). One of the sample applications included with ODS does just that.
Additional reference words: Triggers, rules, stored procedures