Extracting select data from excel sheets

Hello.

I am currently trying to merge data from two excel sheets (A and B) into a third excel sheet (C):

A = xlsread('file1','sheet','column1');

B = xlsread ('file1','sheet','column2');

C= xlsread('file2','sheet','column');

A and C are similar; A has every value of C, but C does not have every value of A (i.e., A is longer and contains values that are not present in C). Moreover, A has corresponding values in B. I need to extract all of the values for A and B that correspond with C while leaving all other values as NaN. Is this possible?

[dpb]

Makes no sense -- you start off with no C but then the description of the development of the content of C is dependent upon existing C content.

Try again to describe what A and B contain and what merge operation you're after.

Probably a short(ish) example would ease the comparison.

Look at the various join operations and/or ismember and related friends...