Open hex workshop and then choose open file. Browse to the folder which you installed Hoyle Card Games 2005, this is usually "Program Files\Sierra\Hoyle Card Games 2005". Once there you should find a folder called user0 ( 0 being the first player and 1 being the 2nd..so on and so forth) In that folder you will find a file called rchk0.log (0 or anothernumber depending on the player). Now load that file into hex workshop.

You want to go to the Edit menu and from there select Goto. When the dialog box opens up you want to make sure the radio button for "HEX" is selected and the radio button for "Beginning of file" is selected. In the offset box put "00000005" without the qoutes and press Go.

This should have brought you to the middle of the 3rd column, what you want to do is type 3 sets of 99 like this... 99 99 99. Save the file and then open up Hoyle Card Games 2005, the player you edited should have roughly 10 million dollars in Hoyle Bucks.
First off this cheat requires the use of a hex editor.