Extracting Dates Data From The Same Sheet?

I'm attaching the test file with one example sheet. Within the same sheet, there is month end dates in column A, and from column B till column E, there are 4 variables (Foreign LT Debt, Local LT Debt,Foeign ST Debt and Local ST Debt). Their respective month end values are already given from column G till Column R. How it is going to be extracted is that against each effective date for that variable (Foreign LT debt, for example), the Rating is given under Rating header. So, for instance, for Foreign LT debt, rating from 25/8/1993 till 4/2/1997 is BB-. So, for all CELLS in column B between these dates, the rating should be BB-. Before that, since there is no value given, I want to put it NA. I have filled the values in column B for demonstration. I want to write a function or perhaps a macro to do that automatically for these 4 variables. There are 50 + sheets with the same layout, so I hope the macro or look up function have not to be written 50+ times.