I saw a forum for Linux, but not Unix. I have a question regarding grep. Please move me if necessary.

The grep I am using is GNU utilities for Win32 and I am using it to search my legacy ASP files for CreateObject. Most of the ASP files I've converted to .NET, but some remain. We are moving from a hosting company to our own servers and I need to make sure all the 3rd-party software that my web application interfaces with will be available for the ASP pages.

There are tons of CreateObject ADODB.Connection. I don't care about these. So can I pipe the output of grep into another grep and say exclude ADODB.Connection? I tried this,
grep CreateObject *.asp | grep -L ADODB
which returned
grep: writing output: Invalid Argument

Thanks for any help.