Upon data entry - Selective locking of few cells to prevent further editing of its content

Hi,
I would like to know if its possible to selectively lock certain cells in a row based on entry of specific data in one cell?

Example, I have data to be entered from Columns A to H,
In Row 1, Col A= auto enters today's date and time (I use Now() function), the moment some data entry is made in Col B.
Text or numeral data are entered in Col C - E.
Upon entry of any data in Col E and moving out of that cell, I would like to have the cells from A - E of Row1 to be locked, but should keep Row 1 Col F-H and further open for additional data entry.

I may enter data in Col F - H on some other day or even same day at a different time.

In Row 1, Col H= again auto enters date and time using Now() function, the moment some data entry is made in Col G.
Col F contains some drop down list data.
Here again upon entry of data in Col G resulting in date entry in Col H; these cells should also get locked, allowing further data entry only in Row-2

The problem I face while using Now() function is, when I open the file on some other date, all the dates changes to current date, which should not happen.

Can this be done? If so I would appreciate if someone could help me in this regard.

Also, I found out that excel files with formulas or macros once uploaded in Google as documents for online data entry, the formulas are not uploaded.
I had to re-enter all the formulas on the excel document after uploading. Is there any way to upload with all formulas and macros functional?

I also intend to use the above requirement both by working on my system and also through online data entry.
all help extended to this regard will be immensely appreciated.
thanks in advance.
Regards
Daavis

Hi,
Just wondering whether my query was too complicated...no replies yet.
Can any one tell me whether this can be achieved?
Please help.
Regards
Daavis