Need to write a program for tick tack toe in VBA

Computer vs User. Use cells A1 to C3 to hold marks. After user enters X, they chick a "go" button; program first determine if the player have won or tied(full board). If so, show "Player Won". If not, computer picks where to move by random (first check that chosen space is blank), and program checks again for win or tie. If neither, program waits for user to ciick " go" again. Ask if they want to play again. If so, clear the board. Keep a count in the spreadsheet of how many games computer vs. player has won. Also ask if they want to reset the count. Check for invalid input by user. Need to use main program, need subprogram, loops,