Set a field with a Default value

Dear,

In the users section we have a field called Default Search Record Type. The Default value is Contact.

I would like to change that to 'Company'.

I tried the Expression: [{Default Search Object}]=LookupName(DefaultSearchObject, Company)

but now the default value for the field is All (the first value of the picklist)

I have the same with the Work phone# this should have the default value (0).

Could you help me with this?

Thank you!

Regards,

Fiona