Got it working!
Thanks for the help. Here's the line I ended up with:
tar cfvz filename.tgz `find ./200* -ctime +60 ! -ctime +90`
The log files are from a Checkpoint firewall. I only want them left there for 60 days and then I pull them off to a server with a CD burner. All the names begin with yyyy, hence the 200*.
Now If I can just virtualize the filename and automate the FTP.....