PHP writing to excel: Will Excel sequences get updated if I change a value where the excel sequence starts.

[Rishikesh Yardi]

Hi, I have a sequence of cells where I pick the value in the A1 Cell in excel and add 10 to it in A2. Similarly I add 10 to A2 in A3. 

My question is:

1) Can i overwrite only the A1 cell values using Php without disturbing the other formulas?

2) Will overwriting the A1 cell update the entire sequence or will I have to manually open the excel file for the values to be recomputed? 

Basically what I want to do is have a complex spreadsheet that is derived from 4 main values which differ everyday. Can I add this to the spreadsheet saved on the server without disturbing the formula cells and writing those 4 values from my db. After that I want to read the final cells and see the values updated by the formulas working on them. 

Is this possible? 

I have attached a sample spreadsheet just to make it easier to understand the question. If I modify the value in the A1 cell using Excel Php writer, will and read them using the Php Reader, will I be reading the updated value or the old value? 

Also is there a way to lock the cells in between because I don't want to edit these even by mistake. 

Thanks for your time. 

Cheers!