Hello,

Are you trying to dynamically change the items of a combobox in one cell based on the selection of a combobox in another cell on the same row?
If that is the case, the KB article below explains how to do it.

HOWTO:How can I change the drop down list on a cell by cell basis in UltraWinGrid
http://devcenter.infragistics.com/Support/KnowledgeBaseArticle.aspx?ArticleID=4878

UltraGrid demonstrated in the above page has two columns, 'Region' and 'State'. Based on the selection on the 'Region' column, you will see the different items in the 'State' column.
What you will need to do to achieve this functionality is to assign a datasource of all the possible items to the 'State' column combobox. You will then use UltraGrid's BeforeEnterEditMode event to populate the datasource looking at the value of the 'Region' cell and assign it to the combobox of the particular cell.

Please let me know if I may be of further assistance.