Copy Problem (progression in formulas)

[Den]

I have the first three cells and I would like to copy down but with
the same progression as shown;

=Sheet1!$E7*DAY($A7)+Sheet1!$E8*Sheet2!$D$5-DAY($A7)
=Sheet1!$E13*DAY($A13)+Sheet1!$E14*Sheet2!$D$5-DAY($A13)
=Sheet1!$E19*DAY($A19)+Sheet1!$E20*Sheet2!$D$5-DAY($A19)
**not a blank line here** **just to show**
=Sheet1!$E25*DAY(A25)+Sheet1!$E26*Sheet2!$D$5-DAY(A25)
=Sheet1!$E31*DAY(A31)+Sheet1!$E31*Sheet2!$D$5-DAY(A31)
....
....


Just can't find a way to do this; copy/paste doesn't work: I'm doing
something wrong.

Any suggestions?

Den