2000x3 decimal matrix to binary matrix conversion with different size for each column

I actually got support one of the contributor in this website but another thing I have to solve and it is, I have 2000x3 decimal matrix in a .txt file and I want to make it binary matrix but first and second column must be 8-bit and third column 16-bit, also matrix consists negative numbers. How to solve this?

Also I inserted the .txt file.

My code is:

A = readmatrix('test_input_xyz.txt');
[sz1, sz2] = size(A);
A = reshape(A,[],1);
B = sdec2bin(A,16);
B = reshape(string(B),sz1,sz2);
writematrix(B,'Myfile.txt','Delimiter','tab')

[Stephen23]

Original question:

https://www.mathworks.com/matlabcentral/answers/485019-conversion-of-2000x3-decimal-matrix-txt-file-into-binary-2000x3-txt-file