Joao,

DO CASE is an alternative to multiple IF statements:

DO CASE
  CASE pnTipoPrcTer=1
    this.parent.LinPrUnit.Value=artigos.n_pvp1
  CASE pnTipoPrcTer=2
    this.parent.LinPrUnit.Value=artigos.n_pvp2
  CASE pnTipoPrcTer=3
    this.parent.LinPrUnit.Value=artigos.n_pvp3
  CASE pnTipoPrcTer=4
    this.parent.LinPrUnit.Value=artigos.n_pvp4
  OTHERWISE
    * the otherwise clause is optional, but can be used to give
    * default code when none of the conditions are met
ENDCASE

You could also build a command string and macro-execute it (this is not tested):

cString=[this.parent.LinPrUnit.Value=artigos.n_pvp]+;
  STR(pnTipoPrcTer,1)
&cString

>if pnTipoPrcTer=1
>this.parent.LinPrUnit.Value=artigos.n_pvp1
>endif
>if pnTipoPrcTer=2
>this.parent.LinPrUnit.Value=artigos.n_pvp2
>endif
>if pnTipoPrcTer=3
>this.parent.LinPrUnit.Value=artigos.n_pvp3
>endif
>if pnTipoPrcTer=4
>this.parent.LinPrUnit.Value=artigos.n_pvp4
>endif
>
>Thank's in Advance
>
>João Batista