Hi,
if you can get the material properties from material supplier you can use it in analysis.
(generally : http://en.wikipedia.org/wiki/Neodymium_magnet#Properties )
You can edit the part insert material properties directly:
Select the part insert elements:
Right-click > Properties...
Field: Metal > To the right "Select..."
"Edit..."
This will be for the specific analysis setup.

You can also create a personal database, to create a material for selection:
tab Tools > New
Property Type : Mold material
To the left of OK button click "..." to giva a name to the database
You now can create a new material.
Or, you can copy from database and change via:
In righ lower corner click "Databases >>"
Select material.
Click "Copy".
Then Edit the material as wished.
Exit with OK.
When you select the mold material, you need to change "All mold material (System)" to "All mold material (User)" to find the your personal database or use the "folder open" button to select a mold material udb-file.
Hope this helps.
Regards,
Berndt

Berndt Nordh