help draw curved line between two points

Hello everyone, I need to draw a curved line beetween two points, how can i do it?

For now I have tried this way but I get a straight line:

clear

close

clc

Pos = importdata("Pos07_12_21.txt");

x1 = [Pos(1,1);Pos(2,1);Pos(3,1)];

y1 = [Pos(1,2);Pos(2,2);Pos(3,2)];

z1 = [Pos(1,3);Pos(2,3);Pos(3,3)];

plot3(x1,y1,z1,"k");

p.s.: pos=

10009.6827000000 49968.6391000000 618.340200000000

10019.7800000000 49979.0046000000 622.162400000000

10027.3819000000 49987.1384000000 619.442100000000

10009.6970000000 49968.6459000000 618.464600000000

10019.7886000000 49978.9978000000 622.301900000000

10027.3794000000 49987.1322000000 619.574500000000

10016.3711000000 49962.0762000000 617.777700000000

10025.5792000000 49972.1036000000 622.192300000000

10034.0286000000 49980.8681000000 619.401100000000

Answer 1

[Chunru]

Pos=[
10009.6827000000	49968.6391000000	618.340200000000
10019.7800000000	49979.0046000000	622.162400000000
10027.3819000000	49987.1384000000	619.442100000000
10009.6970000000	49968.6459000000	618.464600000000
10019.7886000000	49978.9978000000	622.301900000000
10027.3794000000	49987.1322000000	619.574500000000
10016.3711000000	49962.0762000000	617.777700000000
10025.5792000000	49972.1036000000	622.192300000000
10034.0286000000	49980.8681000000	619.401100000000];
x1 = [Pos(1,1);Pos(2,1);Pos(3,1)];
y1 = [Pos(1,2);Pos(2,2);Pos(3,2)];
z1 = [Pos(1,3);Pos(2,3);Pos(3,3)];

plot3(x1,y1,z1,"k");
hold on
% Interpolation to make it as smooth curve
xq = linspace(x1(1), x1(end), 51);
yz = interp1(x1, [y1 z1], xq, 'spline');
plot3(xq, yz(:, 1), yz(:,2), 'r')