I think I understood that part already. The question though, is are the values being entered always going to be of the same form?

For example
Value 1: 2000
Value 2: 123,456

Even though the lengths are different, it's only 1 string of numbers being added to each one.

I'm not too familiar with dialogs, but unless there is some specific reason you need it to be 2 input fields in the same box, using $$? and $gettok should be sufficient enough for you.

Here's a simple example of what I mean (no error checking):

Code:
alias getinput {
  var %x = $$?="Enter 2 values separated by a space"
  echo -a Value 1: $gettok(%x,1,32)
  echo -a Value 2: $gettok(%x,2,32)
}


Type /getinput and it will prompt you to enter values and then echo them to the active window.