Using SUM And Performing Subtraction On Columns

I need to do SUM on a column values and then subtract it from the SUM of values on a column from another table. I am using SQL server Management Studio, but getting the errors on the following Query

SELECT note_id, cap_int_amt)- SUM (ttl_cap_int_amt) as SUM1,
sum(orig_fee_amt)-sum(ttl_qualfyng_fee_amt) as SUM2
FROM [spstrd00_starrpt].[dbo].[rpt23t]
where [rpt20t].note_id =[rpt23t].note_id

ERROR Message
Msg 208, Level 16, State 1, Line 1
Invalid object name 'dbo.rpt23t'.
Msg 4104, Level 16, State 1, Line 7
The multi-part identifier "rpt20t.note_id" could not be bound.
Msg 207, Level 16, State 1, Line 8
Invalid column name 'ttl_qualfyng_fee_amt'.