This all has to be done via User Interface automation. There are no activities or APIs available specifically for Lotus Notes. The biggest problem with Lotus Notes is that each page can be created completely differently depending on the database or customization that you apply.
If you search the forum there are other topics on Lotus Notes here 
ashokkarale
KevinE
Anil_G
Rule_Outlaw
lrtetala
A_Learner
Kanika_Saluja