search and replace field parameter

[Martin Bozelie]

Dear group, I have another question, which is a follow-up on my
earlier question:

I have a number of documents, in which i need to do a find and
replace. There is a field in the header of page 2, with the following
code:

REF Reference \h \* MERGEFORMAT

I want to change it into:

REF Reference \h \* CHARFORMAT.

How do I do this kind of search and replace?

Second problem is, that this field is located in the document header,
and it only becomes visible when people get to page 2! (it is a header
which is not on page one, as set in document settings.)

I would really appreciate your input on this one.

regards, Martin