Assuming you would like to know how to create combinations for members in meetings using Excel, here are the steps:

1. Open a new Excel workbook.
2. In cell A1, type "Members".
3. In cell B1, type "Meetings".
4. In cells A2 through A6, type the names of the members. In cells B2 through B5, type the names of the meetings. 
5. Select cells A1 through B6. On the Home tab, in the Styles group, click Conditional Formatting.
6. Click Highlight Cell Rules, and then click Duplicate Values.
7. Click OK.
8. The duplicate values in column A are highlighted. 
9. To create combinations for members in meetings, you can use the RANDBETWEEN function. In cell C1, type "Combinations". 
10. In cell C2, type =RANDBETWEEN(1,COUNTA($A$2:$A$6)). This formula generates a random number between 1 and the number of members. 
11. In cell D2, type =INDEX($A$2:$A$6,C2). This formula retrieves a member's name based on the random number generated in column C. 
12. In cell E2, type =RANDBETWEEN(1,COUNTA($B$2:$B$5)). This formula generates a random number between 1 and the number of meetings.