You can use this free script from Popcorn Island
https://www.popcornisland.com/2009/03/final-cut-2-after-effects/
Take the shots you want to effect in AE, drop them in a new timeline, export the timeline as an XML file. Before opening AE, drop the popcorn island script in the scripts folder in your AE application folder. Open AE, under the file menu go to scripts, select the script from popcorn island, it will ask you for the XML file to open, select it and your FCP sequence will open in an AE timeline. The script allows AE to see the same media as FCP so you don’t have to export quicktime files from FCP. Once you’ve effected your shots, then export a quicktime as you normally do out of AE. I usually put the AE quicktime on a layer above the shots I’ve cut in the FCP sequence just so I know what shots I used originally and if you need to create an annotated EDL.
Hope this helps.
Cheers,
Jamie