how to use vlookup(excel) functions and then use solver(excel) for optimization in Matlab?

Hello Everyone, I am working on a problem where I have data(signals) from two sources-electrical response and image response and they have different frequency and also there is a lag between them.I have 1 million data points in electrical data and 40000 points by image analysis.What I want to do(has been doing in Excel) is to first use vlookup function of excel which looks up for same time(or approximately same)(here the time is adjusted as actual time+lag) as that of image in electrical data and then at that time I use the signal value of electrical data and after that I calculate the error/difference in the image data value and electrical data value and I do this for all the 40000 image data points and then I sum up all the errors.My aim is to minimize this total error by adjusting the lag and hence essentially finding the lag or trying to align the two signals with maximum correlation possible.I came to know that excel might not be the best software to do this and I can do this in Matlab.Any help would be grateful

Akshay