So if I understood you correctly, you want to set the cell.Hyperlink.Location to point to the result of worksheet.Cells.FindText(searchText, false, false, out objectRow, out objectColumn);.
In that case, try this:
var workbook = new ExcelFile();
var worksheet = workbook.Worksheets.Add("Sheet1");
var cell = worksheet.Cells["A1"];
cell.Value = "Link Cell";
string searchText = "Search Cell";
worksheet.Cells["A2"].Value = searchText;
int objectRow, objectColumn;
worksheet.Cells.FindText(searchText, false, false, out objectRow, out objectColumn);
cell.Hyperlink.Location = CellRange.RowColumnToPosition(objectRow, objectColumn);
cell.Hyperlink.IsExternal = false;
workbook.Save("output.xlsx");