Foreign key problem while loading the Target table for first time

I have to load data into to Table (sample script for the table)

USE DevSamples
GO
IF EXISTS (SELECT * FROM sys.objects WHERE name = 'SSIS')
	DROP TABLE dbo.SSIS
	GO
CREATE TABLE dbo.SSIS
(
	Id			bigint			NOT NULL	IDENTITY,
	SSISCode    bigint      NOT NULL  DEFAULT (8000)  ,
	ProcCode    bigint        DEFAULT (1),
	Value		char(392)	NOT NULL	DEFAULT ('just stuff')
)
ALTER TABLE dbo.SSIS ADD  CONSTRAINT [SSIS_PK] PRIMARY KEY CLUSTERED 
([Id] ASC)
ALTER TABLE dbo.SSIS  WITH CHECK ADD  CONSTRAINT [FK_SSISCode_ProcCode] FOREIGN KEY([ProcCode])
REFERENCES dbo.SSIS([Id])
ALTER TABLE dbo.SSIS  CHECK CONSTRAINT [FK_SSISCode_ProcCode]
CREATE INDEX ix_SSIS ON dbo.SSIS  (ID)
SET NOCOUNT ON
GO
INSERT INTO dbo.SSIS DEFAULT VALUES
GO 10
SET NOCOUNT OFF
GO
-- Just to have a few different values
UPDATE	dbo.SSIS
SET		SSISCode  = (SSISCode - id)
UPDATE dbo.SSIS
SET		ProcCode  =8 WHERE ID > 5
UPDATE dbo.SSIS
SET		ProcCode  =2 WHERE ID < 4
Select * from dbo.SSIS

FK Column ProcCode references ID column of the same table. I am trying to load the data from a Excel source. Excel data looks like this..

SSISCode, ProcCode, Value
-----------------------------
7999,7998,'just stuff'
7998,7998,'just stuff'
7997,7998,'just stuff

1. ProcCode will be resolved via a Lookup with SSISCode and insert ID value.
   --When the table is empty how can I know the value of ID column for first time load?
2. I can initially load NULL to ProcCode and then update the value but for this I need
to have a staging table. Is there any better way to resolve the issue without a staging table?

Thank you for answerign my question.