쨘 is one kind of onomatopoeic words, like 쉿(hush), 우와!(wow), 펑(bang), 쾅(boom). and I guess the meaning of sentence what you wrote above is 'I want to make a toast / Let's make a toast.' because some old men such as company's bosses usually say this sentence in front of there staff in korea.

쨘 is mimetic(?) word. this is used when you take surprise actions. 여러분들 앞에 쨘 하고 싶다 seems little awkward, 여러분 앞에 쨘하며 나타나고 싶다 is less weird. (쨘 is awkward word to me...) And means: "I want to appear surprisedly to all of you."