Well, if you want to use the lest cost routing, you have to do some thing like this
1 - Roddi - to create the destination with tha route or direction of you want to use
2 - only if you have LC time of day you have to send the command LCTDI

AY= [ ,TIM1= ] [ ,FDT1= ] [,TIM2] [ ,FDT2= ] [ ,TIM3= ] [ ,FDT3= ] ;
3 - lcddi:tab=fdt,tzone=?,frct=?,pre=(destination); the pre can be your route code, if you don't have time of day options you don't need the tzone parameter
4 - LCDDI :TAB= [,ENTRY=...] [,TRC=] [,TRC1=] [,PRE=] [,PRE1=] [,CONF=] [,ACCT=] [,MIN=] [,MAX=] [,ACF=][,FRCT=...] [,TOLL=] [,CBCS=] [,BTON=] [,TNS=] [,OSA=];
now you can insert what you want in the pre parameter.