Is it this what you are looking for?
pts = {{{0, 4, 23}, .092}, {{.2, 6, 26.2}, .262}, {{.4, 23, 28.9}, .506}, {{.6, 25.6, 32.5}, .692}, {{.8, 28.9,
39.8}, .886}, {{1, 50, 40}, .942}};
power = InterpolatingPolynomial[pts, {x, y, z}]
Manipulate[
Plot[power /. x -> xx /. y -> yy /. z -> zz, {xx, 0, 1},
PlotRange -> {0, 1.2}], {yy, 0, 50}, {zz, 20, 40}]