Addtional column in change form in Admin

Question

Hi

I need to show a column in admin section when user edits a specific model object(there will be only one object of this model).This column is not part of the model.And this column will show default values of each field of the model,how can I do this?

for example - the model has age,name as columns.So, when the user edits,I want to show another column like DefaultValues - which displays some values for age and column fields.