Macro for vacation accrual needed

I am working on a vacation accrual sheet & need some help please:
Every pay period, the monthly accrual is logged in columns labeled “A”. The accrual is done by placing an “x” in row 2 of each period (eg. O3, Q3, S3, etc). This will populate the entire column with a number that corresponds with the length of service period defined in L, M, N. So, if the person has been in the company for 1-4 years = 1, 5-9 years = 2 and for 10+ years = 3. When someone moves from one category (L, M, N) into the next, it sets all previous accrual fields to that number. For example: moving from the 1-4 yrs category (which would show a “1” in O, Q, S, etc. into the next one of 5-9 yrs (which should be a “2” in the accrual colums) then all previous “1”s end up as a 2.
I need a solution that copies the current accrual column onto itself with its values only. I created a Macro for that but the problem with this is that I have to create about 100 of those, one for each “A” column.

OK, after some research I found a VBA code I think I can use if there is one thing that can be added. The code I found is this?

Sub NoCopyAndPaste()
Sheet1.Range("A1:A10").Value = Sheet1.Range("A1:A10").Value
End Sub

Is there a way to manually input the range (........:.....) before I run the macro, using something like a userform or so??? I don't want to overwrite the formulas in the future, just in the past, so I want to enter the range to copy & paste manually?!

You could calculate the years of service for each "A" column based on the dates in row 3.

Put this in O6 and copy down and across.
=IF(AND(O$2="x",$D6>0,$D6<O$3),LOOKUP(DATEDIF($D6,O$3,"y"),{0,5,10},{1,2,3}),"")

Hi AlphaFrog,
sorry for not replying earlier, but I didn't have a chance to try out your solution. And it works perfectly fine. Thanks so much!!! I really appreciate your help!!!

You're welcome and thanks for the feedback.