Dear Sir
May I know, How to write macro code for two date difference for 100 rows. And If difference result more than 60, I will write "Lost Follow up" text in excel column.

Moved, you "asked" your question as a answer to someone else's question.
Please be careful. If you need to add more info, merely answer your own question to add more details

If the two dates are in column A and column B...

A1 - earliest date
B1 - later date

This formula in row1 in an empty column:

=IF(B1-A1>60, "Lost Followup", "OK")

Copy that cell down the column you put it in for 100 rows.