@Carl Love 

Thank you very much!! it was extremely helpful!

@Carl Love 

That seems to have fixed that error! thank you very much. 

When I continue with my code I got the error: Error, unable to execute seq

> with(plots), with(ColorTools), with(LinearAlgebra), with(RandomTools), with(ExcelTools);
> with(ExcelTools);

A := `<|>`(`<,>`(1, 2, 0, 2, 3, 4, 3, 4, 7, 9, 5, 3, 4, 6, 7, 8, 3), `<,>`(0, 4, 7, 2, 2, 2, 4, 5, 6.5, 7, 5, 3, 2, 5, 9, 0, 1), `<,>`(1, 5, 2, 0, 4, 1, 2, 3, 4.3, 7, 8, 5, 3, 2, 9, 6, 4));

J := convert(Import("test.xlsx", "Cartesian", "E2:G18"), Matrix);
[Export, Import, WorkbookData]
> B := Matrix([[1], [.2], [.1], [.8], [.5], [.6], [.8], [.764], [.234], [0.4e-1], [.89], [.36], [.687], [.627], [.689], [.328], [.139]]); H := convert(Import("test.xlsx", "Cartesian", "D2:D18"), Matrix);
> C := [seq(Color([H[i, 1], 0, 0]), i = 1 .. RowDimension(A))];
Error, unable to execute seq
> pointplot3d(J, color = C, axes = boxed, symbol = solidsphere, symbolsize = 40);

@Thomas Richard 

I know get the new error: 

Error, invalid input: `convert/Matrix` expects its 1st argument, M, to be of type {Array, Matrix, Vector, array, list}, but received Import("test.xlsx", "Cartesian", "E2:G18")

in place of the old one. Though my excel file is an array.