append the two sets of data side by side at different times using"write to spreadsheet file vi"

[fenny]

i want to write two sets of data to the same file, but not concurrrently. I mean that I write the first set of data to a file and then after maybe a certain days or weeks, I append another set of data to the existing file. according to my knowledge , I can only append the second set of data "head to end ", but what i prefer is to write the two sets of data "side by side", I mean eg. if I write the first set of data to the first two columns of the spreadsheet file, I wish i can write the second set of data to the third and foruth columns of the same spreadsheet file.

[djadjok]

Here the problem is the sequentual nature of a data storing in the file itself. If the file format is "line by line" - then normally, when you append data to a file - "head to end" in your terms - you do not obliged to rewrite data previosly saved. But at the same time if you want to add new columns to this kind of file you must not append, but insert data in the file - thus resulting in complete rewriting of the file - i.e. you'll be obliged to read your file first, rearrange/resize array to add new column and save it from the very beginning. It doesn't seems to me as a good approach.