Hi Phanees,
Are all of the 100s of diagnosis options in the same 'field' in the application panel or are they all different fields on the screen?
If one field:
Spy the field and read it. After that, extract data to a text or collection data item. Select what you want.
If multiple fields:
You probably have to read them all. They are likely identical to eachother with the difference of the matching index. This matching index is sort of a sequence number for identical fields. If more identical fields are found, they can be read by setting the match index to 1 for the first, 2 for the second etc. You can read each field into a row of a collection. Once you've read them all, you can select from the collation what you want to work with.
------------------------------
Happy coding!
---------------
Paul
Sweden
------------------------------
Happy coding!
Paul, Sweden
(By all means, do not mark this as the best answer!)