Que operação é essa?

Essa é a parte de um programa em C no qual estou tentando passar para pascal.Porem tem uma linha que eu não compreendo oque o programa tenta fazer.

typedef struct {WORD MagicNumber; BYTE HeaderType; BYTE SubChannelNumber; WORD NumChansToFollow; WORD Reserved1[2];DWORD NumBytesThisRecord; WORD Year; // Computer date when this record was savedBYTE Month;BYTE Day;BYTE Hour; // Computer time when this record was savedBYTE Minute;BYTE Second;BYTE HSeconds; // hundredths of seconds (0-99)WORD JulianDay; // Number of days since January 1WORD CurrentLineID; // [i] Current line ID from serial portWORD EventNumber; // [O] Last logged event numberBYTE ReservedSpace2[11]; // Currently unused} XHEADER;int infl=0;unsigned int amt;unsigned char *buffer = NULL;void ReadFile(int infl) {/***************************************************************************************/// Given a handle to on open file, read through the file and// print out some data about it.//// Read the file header//if (ReadHeader(infl, FileHeader) == FALSE) return;ProcessHeader(FileHeader);//// Read the file one packet at a time//while ((amt = ReadFormatFileData(infl, buffer)) != 0xFFFF) {//// Buffer now holds a single record which can be processed // here. The return value from ReadFormatFileData()// holds byte length of the data record //XHEADER PingHeader = (XHEADER ) buffer; // o que ele esta fazendo ??????????????????switch (Header->HeaderType) {case _HEADER_S: ptr = "SNR "; NumSnr++;ProcessSnr((XHEADER *) PingHeader);break;.......................

Se alguem souber oq a linha em vermelho significa por favoooorr me dê uma luz.

a minha duvida é saber oq significa (XHEADER *) oq esse asterísco significa?

Obrigado a todos q puderem me ajudar.

Rubens