postbit template to show number of days registered ?

[eva2000]

How can i add under the post count of each user the number of days they have been registered on my forum ?

i.e.

[b]Username]/b]
User title:

Registered:
Location:
Post count:

Days since registration: XXX

where XXX is the number of days they have been registered..

i'd like to have this available in beta 4 where it can be added with some varibale like $daysregistered

so that it can be used as an alternative or additional to the post count.

easy to do ?