I am using this If function to find : =IF(D10="","",FIND("&",D10)>0), let how do I proceed by using this logic. I need to use " instead of & in the above logic.
I think you might be looking for this...
=IF(D10="","",FIND("""",D10)>0)
Note that there are 4 quote marks (what you are calling double inverted commas) as the first argument in the FIND function, not 3. Because quote marks are used delineate a text constant for Excel, you cannot use a single quote mark by itself inside a set of quote marks because it confuses Excel as to where the constant text begins and ends. Excel uses 2 quote marks next to each other inside the quote marks delimiting the text constant for each single quote mark that should end up in the text constant.
See if this makes it clearer. Put this formula inside a cell...
="This is a quote mark "" inside other text"
See the two quote marks next to each other in the formula? Look what happens to them in the cell... they become a single quote mark. Now lets show you why you needed 4 quote marks in that FIND function. First, remove the text constant part after the internal double quote marks to get this formula...
="This is a quote mark """
Now look at the cell with this formula... those 3 ending quote marks are actually 2 internal quote marks and the last one is the quote mark delineating the text constant. Okay, now remove the text constant in front of the double quote marks...
=""""
Now the cell displays a single quote mark. That is where the 4 quote marks come from in the FIND function... two internal ones for the single quote mark to be outputted and two surrounding it to mark a text constant.