Adding Multiple Deadlines to One Task

I am a new user to Microsoft Project. My company are currently using Project 2010 so I am having to use this version.

I noticed that I can add deadlines to individual tasks, which is really useful for me. When I do this I get a Green arrow at the end of each task. I now want to add a second arrow of a different colour to the same task. The reason for this is that within my company each task must be peer checked, so I want to add a deadline when a task must be submitted for peer checking and then a final deadline (the green arrow) when the task must be fully signed off.

I know I could just use multiple tasks to show this but I want it to be shown on one bar of my schedule.

I hope that makes sense.

Thanks,
Tom