Possible use of VBA to clear cell content if a search term is found

Hi Everyone,

I've been using this board for a while and learnt a lot thanks to many of your expertise and skill sets. I have searched these boards but have been unable to find a solution to my problem; hopefully something someone can help with?

Key Points:

1. I have a spreadsheet which consists of a number of tabs (7 in total)
2. I am copying data from reports (from a .txt file) into column A of each tab (i.e. reportOne.txt will be copied into tab 1 column A, reportTwo.txt will be copied into tab 2 column A).
3. I then have other reports that are generated at a later date and these will be used to populate column B in each tab (i.e. reportOne_v2.txt will be copied into tab 1, column B etc.)
4. I am then comparing the two columns on a row-to-row basis (as the structure and contents should be exactly the same). Code that I am using (which works fine) is:
   

   =IF(ISERROR(VLOOKUP(A1,B1,1,FALSE)),"No Match","Match")

5. This formula is placed in Column C of each tab and copied/dragged to the last row containing data

My Problem:

1. The reports contains rows of data that I do not want to compare (i.e. I do not want to code above to be present in row C).
2. What I have been doing is looking for search terms using a filter, selecting these rows and then manually removing the formula in Row C.
3. Some reports run into thousands of rows, although many of the search terms have similarities and so the filter works fine, although this method is slow and inefficient and I have a 20 min time-frame to complete the whole task.

Ideal solution:

1. Would it be possible to have pre-defined search terms on a tab-by-tab basis that clears the content in column C if the search terms are matched?
2. Possibly something we can do using VBA?
3. Ideally I would like a button or to run a Macro that clears the content of column C if a row in column A finds a row that contains for example ("machine date/time...")

By doing the above it will drastically reduce my manual work and ensure I complete this task within the set time-frame.

Thanks and kind regards,

Sam