Can this be done in SQL instead of traditional 'CHAIN'?

Hello All;
I am working on an embedded SQL code instead of using the traditional
'CHAIN' suggested by my boss. Now, I am stuck and was wondering if anybody
could point me in the right direction. I am dabbling in quite a few files
but I will try and keep it very relevant. Firstly, here is a little subset
of the data.

  item branch dateeff price  a 1 20060108 15.18  a 3 20060108 38.16  a 2
20060509 48.15  a
20061015 39.12  b 4 20060915 48.36  b 3 20060101 99.12  b
20060710 59.46  b 2 20051225 74.69  b
20051012 18.45  c 1 20050815 10.15  c
20061012 19.04  c 3 20061030 18.77  d 6 20051215 0.79  d 7 20061010 19.65
d
20061015 44.22  d 2 20050512 33.98
Now, here is my difficulty. I am going to join the item later on with my
grand query. From this file this is what I need...
If I pick up an item 'a' I want my query to give the price with the latest
date in 'dateeff' and the 'branch' needs to be blank. So, for item 'a' it
would be '39.12'. That is too trivial. Now, if I want the pricing for 'b'
the latest date is 20060915 but the branch is not blank so I need to look
the next latest date and see if the branch associated with that date is
blank and if it then I need to pick that pricing. So, it is 59.46. For item
'c', it is 19.04. For item 'd' it is 44.22.

I hope I have made sense out of my problem. I have been working on this for
the past four hours but to no avail. This is my whole query till now....(if
anybody wants to make sense out of it..:-0))

(My apologies for non-formatted SQL)...

select itmmst.itmnum, itmdsc, unit, vendor, itmlgm, REPLACE(substr(nccxpp,
9, 50), '@', ':') AS $$PATH40, desc, shortdescription, price, dteeff from
(select max(dteeff) as max_date, itmnum from ec30data.itmprc group by
itmnum) maxresults, ec30data.itmmst itmmst left outer join
ec30data.bwixrfbwixrf on
itmmst.itmlgm = bwixrf.nccxcn left outer join testing.catview catview on
itmmst.itmnum = catview.itmnum left outer join ec30data.itmprc itmprc on
itmmst.itmnum = itmprc.itmnum WHERE (maxresults.max_date = itmprc.dteeff and
itmprc.itmnum = maxresults.itmnum)

Any help in this matter would be much appreciated.

Thanks in advance.

cheers,

Jake.