Creating a range from another workbook

Hi guys,
Been looking arround and couldn't figure this one out, hopefully someone can help.

I've got a workbook named r_t.xlsx, and i have a list of data in column A, looking like this, the data however isn't limited to 10 rows, it can get larger and larger:


5047640
5046725
5047144
5048322
5047419
5050415
5050343
5046528
5049578
5048926

I've got another workbook open, and basically I need to compare the values in the other workbook (r_t.xlsx), to a cell in my other workbook. I need to return True if it is in the list, and false if it isnt.

So far i've got it working, but only for one value (A1) in r_t.xlsx worksheet. The problem is that i can get it to work for more the one cell; and thus compare the whole list.

The code i have to open up and read from worksheet to worksheet is as follows (this only reads one line hence A1):
a b c d e
r_t.xlsx sheet1 $A$1 [r_t.xlsx]sheet1!$A$1 =INDIRECT(D1)

The code I have to compare a range is fairly easy and is:

=COUNTIF(E1,A3)>0

A3 being the number i want to compare, and E1 being the Indirect(d1), above.

My question is therefore; how can i compare the whole of column A, in R_T and return true if A3 is in this list.

thankss

Guys check out my other post, i tried t make it clearer!