Can I lift only the part in between my philtrum ridges to round out my lip? (photo)

You have very nice lip contour. I understand your concerns though. 
There are surgical and non-surgical approaches to lip augmentation. Non-surgical approaches include botox (slight lift, reducing gum show) and filler (volume restoration). Surgically, you can have two separate incisions under the nose (italian), one incision under the nose (bull horn), one incision at the red/white upper lip junction (gull wing) or two separate incision at the corners, or a combination, depending on your desired look and anatomy.
In your situation, additional photos would be needed such as mouth slightly open to see the relationship of your lips to the upper teeth. 
Consult with an experienced lip surgeon for a complete range of options that are appropriate for your situation.

hello ngThere various procedures available for those looking to carry out lip enhancement, i would advice you set up an appointment with a board certified PS.

What you are referring to is known as a Cupid's Bow Lift where the skin between the height of the cupid's bow is removed. You are correct in that will make the upper lip more round.