I have never seen a magnetic lasso tool in Premiere Elements (any version of this video editor)?
Is your program really Photoshop Elements (photo editor)? You should be able to find the magnetic lasso tool in
Please clarify your question and supply more details.
If you are really asking about Photoshop Elements, then please post your question in the Adobe Photoshop Elements Forum.
We will be watching for your clarification and details.