Macro in Excel?

[sgtrock40]

The guys at my unit have a spreadsheet that is updated at least 10x's a day. The updates involve adding new line items to the bottom, and deleting old lines from wherever the completed ones are on the list. The list needs to be numbered, and re-numbering would be a simple drag down except that the sheet is also color-coded and dragging the number column down drags down the color(s) associated with the fields highlighted. Is there a way to have Excel autonumber the fields after each update is done, like when the form is opened or closed, or possibly having a "button" or some other type of command that would update the number field? I was thinking possibly a macro, but I have next to no experience with macros, and absolutely none with Excel (the closest I've come is in MS Access). Help! Thanks