I am not really familiar with the spreadsheet project. I do not know whether it is a solution or not.
However, of the currently available plugins the most likely one for the type of marking you are doing is STACK. It can take inputs in a variety including string, numerical, algebraic expressions apply a series of tests arranged in a decision tree.
It is able to cope with a wide range word problems in mathematics and physics. This seems to me to be what you are doing. The student is presented with a problem which has a partially complete spreadsheet and is asked to interpret it solve the problem and supply some derived answers. You could set up the problem with a screen shot of a spread sheet and then ask the student enter selected values. Alternatively, STACK has a syntax in which students can enter tables.