Wǒ shùnbiàn wèn yīxià, míngtiān de huìyì jǐ diǎn kāishǐ?
By the way, what time does tomorrow's meeting start?
Tips
usage
顺便 implies doing something extra without special effort because you're already doing something related. It softens requests: 顺便帮我... (while you're at it, could you help me...).