This is the Metastock code for an indicator called Better Bollinger Bands. Can anyone code it in MT4? Any help would be appreciated.

Better Bollinger Bands I
pds:=Input("Periods",2,200,20);
sd:=Input("Standard Deviations",.01,10,2);
alpha:=2/(pds+1);
mt:=alpha*C+(1-alpha)*(If(Cum(1)<pds,C,PREV));
ut:=alpha*mt+(1-alpha)*(If(Cum(1)<pds,C,PREV));
dt:=((2-alpha)*mt-ut)/(1-alpha);
mt2:=alpha*Abs(C-dt)+(1-alpha)*PREV;
ut2:=alpha*mt2+(1-alpha)*PREV;
dt2:=((2-alpha)*mt2-ut2)/(1-alpha);
but:=dt+sd*dt2;
blt:=dt-sd*dt2;
dt;
but;
blt