Raja,

Adding a complex component to the tline will not give you loss,  for a single frequency you could look at it as a starting angle on a tline of a impedance |a+jb| arg(a+jb) or a tline of characteristic impedance in series with an inductor at a single frequency.
Be careful using this over frequency its even less of what you are looking for, since complex numbers always have a frequency component tied to the complex number.  1/sC or  s*L etc.. One way to approximate a lossy tline is to break it into smaller sections where you can approximate the loss by adding a resistor to an AC ground and or a series resistor often as your needs require.  
To be even more accurate a lossy Tline has several lossy mechanisms.  The three dominant are dc resistance loss due to frequency dependent dielectric constant Er(f).  And finally skin effect which is basically a resistor R=Rdc+Rse*sqrt(f/fo) where fo is the frequency where the skin effect starts effecting the resistance.

http://rfcooltools.com

Dear Raja and dear vp1953, most of the rf programs use to the kurowava formulation, however if you would use any formulation given you have to think that (az+b)/(cz+d)  is a mobius tranformation that maps lines to circles or circles into circles. the smith chart is the result of (z-1)/(z+1) applied to a grid shape. if you use the complex normalization impedance you still get (z-1)/(z+1) after simplifications but you might get a module bigger than 1 since z is not anymore in the RHP. You cannot see this in the rf tools since mostly they use another formulation: the kurowava
On the site http://www.3dsmithchart.com/ you have a free tool that generalizes the Smith chart on the  Riemann sphere and you may solve this pb too with a trick. It is based on a 2011 new concept introduced by my colleagues and myself in a  June MWCL paper.