I'm not sure where are you going with this but you could create a temp variable that takes the random number and compare it later. Also the random function will generate decimals so you have to use int, floor or ceil to round it.
Set varrandom to floor(random(0,300))
Set whatever to trim(tokenat(Dictionary.Get("ReadData"),varrandom,";"))
Since you've set the varrandom to a random number, you can compare this number so you can tell which line it got.