Merge or find & replace data in excell or something else?

[aceparts_com]

I've got an excel problem; I've created a load of HTML templates that are in a spreadsheet in one column and I have some data (descriptions of items) that I want to merge into the html template. I simply need to find %%text%% and replace it with my html description.
Now I can't do a find and replace as it says that the data is too large to search or something.

Anyone got any ideas? It's for some ebay templates btw.....

[aceparts_com]

I basically want to do a mail merge but the documents need to be exported as rows of a spreadsheet (just in case i'm not clear)

[aceparts_com]

Where's Grant when you need him!