The File Menu/Export/Movie is last seen in Premiere Elements 7.
On what computer operating system is your Premiere Elements 12 running? And, have you updated it from 12 to 12.1 yet using an opened project's Help Menu/Updates. Please do that. Among other things, it will get rid of a text/style issue that exists only in the Expert workspace.
For your immediate question...
In Premiere Elements 12/12.1, exporting is done in the Publish+Share section of the workspace.
Remember H.264 is video compression and .mov is a file extension which wraps the video compression.
If you want H.264.mov, then go to Publish+Share/Computer/QuickTIme and select the appropriate 16:9 preset if you have a 16:9 project. Then click on the Advanced Button/Video Tab and customize the preset for H.264 video compression and other properties of the file to be exported.
You might also want to look at the AVCHD (MP4 AVC/H.264).mp4 choices under Publish+Share/Computer/AVCHD.
There is a scroll bar to the right of the Publish+Share/Computer/ choices to be used to scroll down to the rest of the list that you cannot see.
If you need any help with project settings or export settings, please give us some specifics, and we will customize a reply with how to.
As for the FIle Menu/Export, all that remains of that after version 7, is Title for saving titles as .prtl files for use in other projects.