Another Excel query

I have a spreadhseet with a column of formulae of the form

=sheet1!A49
=sheet1!A80
=sheet1!A109
=sheet1!A140
etc.

Each of the increment row references (49 to 80 to 109 to 140 in the example) have to be hand entered as they depend on the number of days in a particular month.

I'd like to create a formula of the form

=sheet1!A[cell above + number of days in month in the date that is in cell A of the current row]

Is there any way of achieving such a relative effect?

Assuming the first date is in A4, then if you put the following in A5

=IF(A4+1<=EOMONTH(A4,0),A4+1,"")

And copy this down column A, it will carry on producing dates till the end if the month.

Example here

If the formula got a little more cunning, it could leave a couple of blank lines and then start the next month, but I am not sure I quite understand your requirement.

Following on from philippercival it's something more involved than:
=A4+DAY(EOMONTH(A4,0))
but I haven't time to go into it now, but it involves manipulation of cell references.

Yes, I am afraid I do not quite understand the problem. However to obtain number of days in month in the date that is in cell A of the current row, you can use

=DAY(EOMONTH(A4,0)) (assumes Row 4)

I've no problem in finding the number of days in a month. The problem (minor in the grand scheme of things, but there you go ) is using that value to change the row reference in a formula. That seems to require some sort of dynamic formula reconstruction or some sort of dynamic referencing.

I think it is a variation of the INDIRECT function that you want

see the Microsoft example

Having now had time to experiment, I come up with this:

Using A1:C12 block for example:

A1: 01/01/12
A2: =A1+DAY(EOMONTH(A1,0)) and filled down
B1: A49 REM your starting point, Note no "="
B2: =ADDRESS(ROW(INDIRECT(B1))+A2-A1,COLUMN(INDIRECT(B1)),4) and filled down
C1: =INDIRECT(B1) and filled down

Then Col C is what you are after, I think