This is a very fundamental question. If I have a worksheet (or a set of
worksheets) containing a complicated calculation, how do I refer to this
calculation from elsewhere with different input values (i.e., how do I call
this worksheet) and get its results?

Example: A worksheet called WS has input cells A1 through A2, and results
appear in B1 to B2.

In another worksheet I have a table with 10 rows and 4 columns. Column A
has values 1 thru 10, column B values 11 thru 20. column C is the result of
"calling" WS with the values A and B of the same row, and should receive the
B1 value of WS. column D again calls WS, but displays the B2 value.

I don't want to make 10 copies of the very complicated set of worksheets WS.

How do I "call" a worksheet and obtain one of many resulting value? I do
not want to do macro programming or VBA programming as it should be
unnecessary (I am doing spreadsheet programming already).

Thanks for all the help, in advance.