Cell Reference Inside DDE Link

Hello all,

In a nutshell what i'm trying to do is have a dde link to a cell in another workbook. That's the easy part. Next I want to be able to change the value in a cell of my "master" workbook and have the dde link update to look for that path. Example:

-The target cell is in MRC.xls-->Sheet1-->Cell D45
-There are multiple copies of this "MRC" spreadsheet in different directories on my server.
-So...I basically want to do this:

=indirect(concatenate("\\Server\",B32,"\[MRC.xls]Sheet1!$D$45))

where cell B32 contains the directory which I want to change (variable).

I've tried splitting the concatenate and indirects up into two different cells which didn't work either.
Also please note I've tried a bunch of other syntaxes and functions to do this but indirect seems to be the cleanest to represent in a question form here.
I wish i could remember more examples of what i've tried but i'm into day 2 of trying to make this work so my brain is starting to get a little muddled!

Many thanks for any help offered.