populate values between sheets

[frapple]

Hi Guys ... help appreciated, hope it's clear.

Vlookup won't work as the first field that meets criteria may be blank.
need to UPDATE field in page1 from data field in page2
ex. page1
d:218 = 2008 e:218= 713110

page2
a:478= 713110 g:478= " blank"
a:479= 713110 g:479= " blank"
a:450= 713110 g:479= 2009

Need page1 d:218 to update to 2009

there is also one other scenario that needs to be adressed:
page2
a:478= 713110 g:478= " blank"
a:479= 713110 g:479= " 2008"
a:450= 713110 g:479= 2009

in this case Need page1 d:218 remains at 2008 (always the lower value)

the match is where column: d on page1 = value of column: a on page2 and column:d not " " ... if matches > 1 d:218 is the lower value from page2: g

Cheers .. Mike