I would like to generate XLS files using PL/SQL. This includes entring text into cells, coloring cells, bordering cells and merging cells.
This may include also:
Check out the work done by Jason Bennett on hist PL/SQL ExcelDocumentType
Starting from MS Office 2003 you can create XLS files as usual XML files. The official documentation is here and some PL/SQL examples can be found here or here.
Everything you've stated in requirements can be done this way.
Hope this helps.
I've done a general XLS from PL/SQL reporting solutions using this techniques: there's hardly any difficult things. Feel free to ask if you have any problems.