Set Expression not exist based on contions

[Channa]

Hi All,

basically

i need to extract ContactID from Lead based on some conditions similarly ContactID from Contact table based on some conditions

after getting ContactID's from both tables , i need to count contactID.Contact not exist in contactid.lead

below i have script level solution but i need this in set expression

this is script level

LeadMQL:
LOAD
Datasource.Lead,
DateMQL.Lead,
QuarterName(DateMQL.Lead) as LeadMQL,
%ID.Lead ,
LeadSource.Lead,
Status.Lead,
%ID.Contact as ContactLead,
Source.Lead,
WOCRecord.Lead,
IsLead.Lead
FROM [lib://Downloads:Data/Lead.qvd]
(qvd) where WOCRecord.Lead = '0'
and Status.Lead <> 'LeanData Auto-Merge'

;

ContactMQL:
LOAD
%ID.Contact,
Email.Contact,
LeadSource.Contact,
DateMQL.Contact,
ContactStatus.Contact,
IsConverted.Contact,
QuarterName(DateMQL.Contact) as ContactMQL
FROM [lib://Downloads:Dat/Contact.qvd]
(qvd)
where not exists(ContactLead,%ID.Contact)
//and QuarterName(DateMQL.Contact) = QuarterName(AddMonths(Today(),0))
//and QuarterName(DateMQL.Contact) = QuarterName(AddMonths(Today(),-3))
and WoCRecord.Contact ='0'
;

i need this is setexpression

Thank you