Any ideas on how to create this CVS tool ?

I would like to take a string of text that exists in a file, that is
under cvs source control, and find out what file version did this
string of text first appear in the file.  A command or script to do
this is what I'm looking for.

For example below is a file called foo.cc,  as an example I would like
to find out how to go about creating a script that would tell me what
version of foo.cc the string "foobar" first appeared.


#include <iostream>
#include <vector>

int foobar()
{
}




I don't use branches in CVS and this might help make the script
simpler.   Any ideas much appreciated.  Not asking for a script unless
someone has one, just ideas about how to go about creating the
script.  What cvs commands would be needed or helpful.