Restrictions on Source Lookup Queries when Source Server Type is Salesforce

If the source server type is Salesforce then the following restrictions apply to the Lookup Query:

a Arithmetic operations (+-,*,/) in queries are not permitted;

b The left hand operand in a relational operation must be a field from the search table;

c The right hand operand in a relational operation must be a value, keyword, field from the current table or a variable.