Macro to insert line or remove line depending on cell in column A.

I have a very long list that I need to organize. This is what the format looks like:

H1001
H1001-1
H1001-2
H1029
H1029-1

However, not every number with a -# has a line preceding it with the main H number. In this case I need to insert a line above the first instance of every H####-# as shown below.

H3914
H3914-1
H3917
H3917-1
H3923-1
H3926-1
H3935-1

And in other cases a main H number is shown but no -# lines follow so I will need to remove those lines.

I am at 4000 lines and would like to speed up this process. Any help would be greatly appreciated.

Originally Posted by Richard Buttrey

Why is there no Main Number above H3923-1, H3926-1 and H3935-1?

I think you may need to upload the workbook with some specific examples of a before and after list for both cases you identify.

not every number with a -# has a line preceding it with the main H number. In this case I need to insert a line above the first instance of every H####-# as shown below.

H3914
H3914-1
H3917
H3917-1
H3923-1
H3926-1
H3935-1