Transposing Rows/Columns with Calculations

Hi Experts,

I have only just started using MS Excel and need your expert advice on a transpose macro.
The spreadsheet has a list of Material Codes along the columns (Mat 1 to Mat 3). Each of these is made up of a mix of material codes along the rows (MatA to MatC).

% MatA MatB MatC Quantity
Mat1 20 0 80 1000
Mat2 50 50 0 2000
Mat3 15 35 50 1000

I need to transpose them into the format/result shown below. Basically, I need to get a column to row transpose while calculating the quantities based on the %.

% Quantity
123 ABC 20 200
123 IJK 80 800
456 ABC 50 1000
456 DEF 50 1000
789 ABC 15 150
789 DEF 35 350
789 IJK 50 500

Please advise me on this. Thanks for all your help.

Best Regards,
Sol