I want to find the row in the second workbook which satisfies the following
three criterias and return the number in column D of that row in the second
workbook to the first (original) workbook. Return blank if the number is not
available.
1. the content of column A in the first worksheet = the content of column A
in the second worksheet (text);
2. the content of column B in the first worksheet = the content of column B
in the second worksheet (numeric);
3. the content of column C in the first worksheet = the content of column C
in the second worksheet (numeric and text);

I was trying to use Lookup, Match and Index formulas but didn't succeed.

Thanks much in advance for your help!