Macro to add and delete particular value in a cell

[Natsha]

Hi all,

I been struggling and searching for an macro where I can add particular number to the cells and also delete the particular number.

Example
I have an sheet with header and datas in 2 columns, in column 2 there will be values like 1-1;17-17;28-29 like wise, what I want is
1) if I need to add value of 1-1 the macro should show if there any dulpicates if there are duplicate either it should highlights or delete that number alone.
2) If I need add the value 1-1 to the cell it should add like this ;1-1 at the end of the cell without deleting the existing value

3) if in case the cells has only 1-1 then [delete] should be pasted there in the above format

4) likewise I need to do many number if there an userform like that it would very useful

Kindly help... thank you