Travel planning using TP01

Hi I'm not very friendly with FI-TV.

When I plan a travel, I'd like open automatically subscreen 4130 for Additional destination and 4110 for Comments.

In Add my customer wants check if comment had be filled by user. I've checked exit FITR0003, but seems it's not possible check the content of this field using the exit.

Both features are required by my customer to help the user to fill the travel request with all mandatory data.

Do everybody explain if there a possible solution, using an exit or a BADI ??

Thanks in advance for your help.

Claudio