hi @gmoreno.id i just noticed that i responded utterly senseless on another thread of yours which was actually already answered before in again another thread, regarding the same basic issues. please keep the questions when strongly related to each other to one thread. not everybody skims along all other topics.
regarding your question: first split the airfoil with the cord line, then select both parts and call the command RebuildCrvNonUniform setting the tolerance to 0.001 and max point to 40, it will interpolate a degree 3 curve over your polyline, while not along the vertices but according to curvature. that will not be super low in points but will ensure precision.