The 33-year-old returned to action on Sunday in the goalless draw against Millwall in the quarter-final clash at the Den, and could involved in this evening's replay at Ewood, kick-off 7.30pm.
"Wednesday is a real big game," said Dunn. "From being a little boy one of my dreams was to play at Wembley.
"Unfortunately when we won the Worthington Cup that was at the Millennium when Wembley was being redone, so I haven't quite managed to play there yet.
"So I'm certainly one who is itching to get through this and play at Wembley, it would be a dream come true for me."
Delighted to be finally back playing after a long-standing calf injury, the midfielder knows that after experiencing the rough and tumble of Sunday's encounter, this evening's game certainly won't be easy.
"It has been a long time coming so it is good to be finally given a chance to get on the pitch.
"It is going to be another real battle on Wednesday. I think we have a real battle on our hands, but I'm confident that our quality will come out."
Supporters are advised to get their tickets well in advance of this evening's match as large queues are expected in the run-up to the 7.30pm kick-off.
Tickets are priced at £18 for Adults, £12 for Seniors/Students and £6 for Juniors under 16.