documentclass{article}
begin{document}

begin{tabbing}
hspace*{2cm}=hspace*{3cm}= kill
column1a > column2a > column3a \
column1b > column2b > column3b
end{tabbing}

end{document}

newcommandmytabs{hspace*{2parindent}=hspace{2cm}=hspace{2cm}}
newenvironment{mytabbing}[1][mytabs]
  {begin{tabbing}#1kill}
  {end{tabbing}}

begin{mytabbing}
  >aa >bb\
end{mytabbing}

begin{mytabbing}[hspace*{2parindent}=aa~=]
  >aa >bb\
end{mytabbing}

documentclass[a4paper]{article}
usepackage[showframe,margin=3cm]{geometry}
usepackage{tabto}
parindent0emparskip1em
begin{document}
TabPositions{2cm,5cm,6.5cm,12cm}
xxx  tab{xxx}  tab{xxx} tab{xxx} tab{xxx} tab{xxx} tab{xxx}
tab{xxx} tab{xxx} tab{xxx} tab{xxx} tab{xxx} tab{xxx} tab{xxx}

NumTabs{8}
xxx  tab{xxx}  tab{xxx} tab{xxx} tab{xxx} tab{xxx} tab{xxx}
tab{xxx} tab{xxx} tab{xxx} tab{xxx} tab{xxx} tab{xxx} tab{xxx}

end{document}