auto fill failed

[balu]

dear sir ,
i would like to represent my need in detail my for mula on an accessform
like this
dim xlbook as excel.workbook
dim xlsheet as excel.worksheet
dim xlapp as excel.application
set xlapp = createobject ( " excel.application")
set xlbook = xlapp.workbook.add
set xlsheet = xlbook.xlsheet(1)
xlapp.visible = true
xlsheet.range("a1").value = 1000
xlsheet.range("b1").value = 200
xlsheet.range("c1").formula = xlsheet.range("a1").value -
xlsheet.range("b1").value
xlsheet.range("c2").formula = xlsheet.range("a2").value -
xlsheet.range("b2").value
'**********************
' actually column A and column b values were query values imported.

xlsheet.range("c1:c2").autofill ( xxlsheet.range("c1"):xlsheet.range("c25"))

' here im failing to autofill the formula for the range through code but
' i can with dragging the curser on the excel sheet on column C why ?
so it must be alike this,
a1=100 a2 = 200 a3 = 300
b1= 10 b2 = 0 c3 = 20
c1 = 110 c2 = 200 c3 = 320