SPICE .DC LIN sweep directive w/ variables for START, END, and INCREMENT args
After some additional perusing through various SPICE reference books, I found the following statement at the bottom of page 202 in Paul Tuinenga's book titled SPICE: A Guide to Circuit Simulation &amp; Analysis Using PSpice (2nd ed.) in the section that describes the .PARAM statement:


  Parameters cannot be used in place of node numbers, nor can the
  values on analysis statements (.AC, .DC, .TRAN, etc.) be
  parameterized.