Find Other Procedures Using the Same DLL

First get the dll.

select o.name,c.text from dbo.syscomments c, dbo.sysobjects o where c.id = o.id and o.name = 'xp_cmdshell'

Second, find the other extended stored procs using that same dll.

select o.name,c.text from dbo.syscomments c, dbo.sysobjects o where c.id = o.id and c.text = 'xplog70.dll'

This is from SQL Server Security Checklist.