I am not sure I understand the complete scenario in details, but I think the following technique for getting controls inside template and switching them in IntislizeRow based on the runtime scenario will help:

http://forums.infragistics.com/forums/t/22474.aspx

i have added controls in cell template and made those invisible. now at runtime i decide which one to set visible. that is working okay. But when i write any value in these controls and try to access the value from server, i am not getting the value over there? what can be the reason?

Giving the code on server side while saving my data.

ig.TemplatedColumn col = (ig.TemplatedColumn)gRow.Cells.FromKey("FilterValue1").Column;

                ig.CellItem ci = (ig.CellItem)col.CellItems[gRow.Index];

                DropDownList ddl = (DropDownList)ci.FindControl("ddlVal");

                DropDownList ddlBool = (DropDownList)ci.FindControl("ddlValBoolean");

                TextBox txt = (TextBox)ci.FindControl("txtVal");

                Infragistics.WebUI.WebDataInput.WebNumericEdit wne = (Infragistics.WebUI.WebDataInput.WebNumericEdit)ci.FindControl("numVal");

                Infragistics.WebUI.WebDataInput.WebDateTimeEdit wdte = (Infragistics.WebUI.WebDataInput.WebDateTimeEdit)ci.FindControl("dtpVal");

                if (ddl.Visible) { rowFilterFld.FilterValue1 = ddl.SelectedValue; }

                else if (ddlBool.Visible) { rowFilterFld.FilterValue1 = ddlBool.SelectedValue; }

                else if (txt.Visible) { rowFilterFld.FilterValue1 = txt.Text; }

                else if (wne.Visible) { rowFilterFld.FilterValue1 = wne.Value.ToString(); }

                else if (wdte.Visible) { rowFilterFld.FilterValue1 = wdte.Value.ToString(); }