What is your numbering?
pic1 thru pic99 (example)
pic01 thru pic99
We can go into this in more detail, but the basic approaches
1. Import the folder with your ordered photos into Premiere Elements 11 Add Media/Files and Folder/Project Assets and then drag the folder to the Expert workspace Timeline where the photo thumbnails will be displayed in order.
2. In Elements Organizer 11, order the photos in an Album that you create there, and then highlight all the photos in the Album, right click in the hightlight, and select Edit with Premiere Elements 11 Editor.
In the case of "1", how you order the photos in the folder is independant of Premiere Elements. If they are ordered beforehand, they will be order after import. To get the photos ordered in the folder on the hard drive, you will probably have create your file names accordingly as John T. Smith is eluding to in his questions to you.
How many photos are involved, what are their pixel dimensions, is your Premiere Elements 11 on Windows 7 or 8 64 bit or Mac 64 bit? And, is this a Time Lapse video project in the works?
Looking forward to your follow up with more details.