Set Variable [$I ; Value: $I + 1]
// at this point you can use GetValue ( yourtable::yourtextfield ; $I ) to access a line of text in the field
Exit Loop If [ $I = ValueCount ( Yourtable::yourtextfield ) ]
At the point where you see // is where you'd insert the steps you need to work with a given row of text in the field. You might use Set Field or Set Variable to copy the line into another location, use an If step to check the value at that line, or...?