First a sanity check. If your table has 100 fields or so, I can almost guarantee that your design is flawed. It may not be but normal databases rarely get over 20-30 fields in a table. I would find it interesting to see your table structure.
Next, you don't need to worry about the wizard. Just click Cancel when you put a combo on there. Then you can go to the properties dialog and set these things yourself:
Control Source - field in the table/query it needs to be bound to, leave blank if unbound is wanted.
Row Source - Select the table or query you want or create a query by clicking the Ellipsis (...) that appears when you click into that property and then build a query (don't hit save but just close it and say yes to the question asked).
Row Source Type is normally Table/Query but can be a value list if you aren't using a query or table or SQL statement as the row source but are populating with items separated by semi-colons. Table/Query is best because it is dynamic.
Column Count: should be the number of fields in your row source query or table.
Column Widths: should be set so you can see whatever field or fields you want. You can hide a column by using 0" and show it by using something other than that (no negative numbers). 0";1";0";0";0" would be showing the second column of a five column row source and hiding the other four columns.
Bound Column: this is the column number which provides the value for the combo, and is usually set to the first column which is normally the ID field.
The Store This Value in this field is just saying it is a bound combo box and the Save Value for Later is an unbound combo box.