You need to pass it as an XML parameter.
Edit: quick code from my project to give you an idea:
CREATE PROCEDURE [dbo].[GetArrivalsReport]
@DateTimeFrom AS DATETIME,
@DateTimeTo AS DATETIME,
@HostIds AS XML(xsdArrayOfULong)
AS
BEGIN
DECLARE @hosts TABLE (HostId BIGINT)
INSERT INTO @hosts
SELECT arrayOfUlong.HostId.value('.','bigint') data
FROM @HostIds.nodes('/arrayOfUlong/u') as arrayOfUlong(HostId)
Then you can use the temp table to join with your tables. We defined arrayOfUlong as a built in XML schema to maintain data integrity, but you don't have to do that. I'd recommend using it so here's a quick code for to make sure you always get an XML with longs.
IF NOT EXISTS (SELECT * FROM sys.xml_schema_collections WHERE name = 'xsdArrayOfULong')
BEGIN
CREATE XML SCHEMA COLLECTION [dbo].[xsdArrayOfULong]
AS N'<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="arrayOfUlong">
<xs:complexType>
<xs:sequence>
<xs:element maxOccurs="unbounded"
name="u"
type="xs:unsignedLong" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>';
END
GO