how to code following scaling-in,scaling-out in amibroker

dear freiend,

i am unable to code following scaling-in & scaling-out metods of exits in
amibroker. i want help from all seniors.

my entry is very simple(daily data for trading)

kpl system for entry only & exit as follow:

1 st exit at x % from entry price only 1/3 quantity.(ie 1st profit target)
2 nd exit when exit signal comes from kpl sys remaining 1/3 quantity.
scale-in to initial quantity if new kpl buy signal comes.
releate above scaling-out & scaling-in till filal exit.
final exit all quantity when close below 21 day EMA.

as fokpl system code llow :

//AFL by Kamalesh Langote. Email:[email protected]
no=Param( "Swing", 2, 1, 55 );
tsl_col=ParamColor( "Color", colorCycle );

res=HHV(H,no);
sup=LLV(L,no);
avd=IIf(C>Ref(res,-1),1,IIf(C<Ref(sup,-1),-1,0));
avn=ValueWhen(avd!=0,avd,1);
tsl=IIf(avn==1,sup,res);
Buy=Cross(C,tsl) ;
Sell= Cross(tsl,C) ;

Plot(tsl, _DEFAULT_NAME(), tsl_col, styleStaircase);
shape=Buy*shapeUpArrow + Sell*shapeDownArrow;
PlotShapes(shape,IIf(Buy,tsl_col,tsl_col),0,IIf(Buy,Low,High));
SetPositionSize(300,spsShares);
ApplyStop(0,1,10,1);


thank you all in advance for help.

asitasu.