how to count party total sales bill and display in vch ref

plz help ;;;party total bills count and disply at vch ref
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[Collection : partylast]
Type : Vouchers : VoucherType
Child Of : "Sales"
Fetch : PartyLedgerName,VoucherNumber,amount,date,Reference
Filter : IsSameParty
Sort : @@Increasing : $date


[#Field: VCH Ref]
Set as:$$Number@partysn

[System : Formula]

IsSameParty : $PartyLedgerName = #EIConsignee




partysn : $$Number@partysnn + $$Number:1
partysnn : $$CountNumofLed:$$Lineartylast

 

Use below Code

[Collection : partylast]
Type : Vouchers : VoucherType
Child Of : "Sales"
Fetch : PartyLedgerName,VoucherNumber,amount,date,Reference
Filter : IsSameParty
Sort : @@Increasing : $date


[#Field: VCH Ref]

Set as : @@TotBill

Set Always : Yes

skip : Yes

[System : Formula]

IsSameParty : $PartyLedgerName = #EIConsignee

TotBill : $$NumItemsartylast

 

THANX U SIR