mapNumericCharNames

Map numeric character names to Unicode.
[read/write property] mapNumericCharNames([out, retval] VARIANT_BOOL *map) mapNumericCharNames([in] VARIANT_BOOL map)
By default, XpdfText will attempt to map the numeric character names sometimes used in font subsets to Unicode. This often results in usable text, but sometimes it generates gibberish. Setting this property to false disables this behavior and tells XpdfText to discard text in fonts with questionable encodings.

This setting is global - it applies to all PDF handles.

VB6:
pdf.mapNumericCharNames = False