May not be the most efficient, but this is what I came up with:
Here's my sample data based on my interpretation of your description:
[filename, pathname] = uigetfile('*.xls*','MultiSelect','off');
ScriptFolder = cd(pathname);
A = readmatrix(filename);
x = A(:,1);
y = A(:,2);
z = A(:,3);
for i=1:length(A)
V(x(i),y(i),z(i)) = A(i,4);
end
xslice = [1,2,3];
yslice = [];
zslice = [2];
slice(V,xslice,yslice,zslice)