select * 
from table 
where 
month( date) = month(CONVERT(datetime,'2009-11-26',110))
and 
day( date) = day(CONVERT(datetime,'2009-11-26',110))
Easiest thing is to only send the month and day part from the .NET code.
i.e. perform the right hand side of the where condition in code.
month(CONVERT(datetime,'2009-11-26',110)), can be computed with .NET code
Also day(CONVERT(datetime,'2009-11-26',110)) can be computed with .NET code
And the left hand side, month(date) or day(date) can be done by using DBFunctionCalls.