Talking keyboards, a dominant 11th is easy. Simply play the bass note of the chord desired, usually with the left hand, and a Major triad of the note one step below. Example: C11= C/Bb-D-F or D-F-Bb or F-Bb-D. You have the 1-b7-2(9)-4(11).
Anything after the 7th chord, all you really need is the root, 3rd, 7th, and whatever extension note.maj 11th: 1-3-7-11dom 11th: 1-3-b7-11min 11th: 1-b3-b7-11maj 13th: 1-3-7-13dom 13th: 1-3-b7-13min 13th: 1-b3-b7-13