DTD location for Xerces-C SAX parser

[Irit]

Hi,

I use SAX 1.0 of Xerces-C, and succeed to read XML document and validate it against the DTD.

I would like to know

1. How can I change the directory the parser looking in it, to find the DTD?
2. How can I give the DTD to the parser, in buffer (char*) and not as file?
3. and may be, how will it be with schema?


Thanks

Irit.