find2

Find a text string.
find2([in] BSTR text, [in] LONG flags, [out, retval] VARIANT_BOOL *found)
This function searches the current PDF file for a given text string. It is a more powerful version of find and findNext, adding the ability to search backward, as well as case-sensitive searching.

find2 returns a boolean, indicating whether the search string was found.

The flags argument contains zero or more of the following flags (or'ed together):

Note that these options are read-only properties on the XpdfViewer control, so you'll need to use viewer.find2Backward, etc.
VB6:
' do a backward, case-sensitive search viewer.find2 "Needle", viewer.find2Backward Or viewer.find2CaseSensitive
find2Backward
find2CaseSensitive
find2Next
find2OnePageOnly
find2WholeWord
find
findNext