Excel2007 advanced copying into blank row

Hello, I used a macro to insert blank rows into my spreadsheet. Now I need to copy the exact same numbers into the blank rows and add the letter A to them. I only need this for 1 column not all columns.
ie.
5000
5000A (blank)
5001
5001A (blank)

I need an easier way to do this than click and ctrl drag, then inserting an A!

Thanks for your help!