Something

bool bDataCompare(const unsigned char* pData, const unsigned char* bMask, const char* szMask)
{
    for(;*szMask;++szMask,++pData,++bMask)
        if(*szMask=='x' && *pData!=*bMask )
            return false;
    return (*szMask) == 0;
}

unsigned long dwFindPattern( unsigned char *bMask,char * szMask, unsigned long dw_Address = dwStartAddress, unsigned long dw_Len = dwLen )
{
    for(unsigned long i=0; i < dw_Len; i++)
		if( bDataCompare( (unsigned char*)( dw_Address+i ),bMask,szMask) )
            return (unsigned long)(dw_Address+i);
    return 0;
}