Linked lists

I have some sample code that allows me to save to memory and then dump that memory to a file.
The problem I have is being able to tell this part of the sample code to accept my figures (which comprise of about 4000 figures read from the lpt port)I really would love to know how to capture those streaming figures from the port wrap them in such a way that i could put them in this sample code that i have

          In order for this sample code to simulate a lot of figures it does this
For i = 1 To 4000              
          Set curr.pnext = New Node  
          Set curr = curr.pnext      
          curr.key = i
next i  
I need to replicate this programmatical scenario  with mine