Power Builder - filtro de numeros

amigos su acontumbrada ayuda hago un busqueda de informacion con la sentencia pero al validar la informacion con numeros, no ejecuta la busqueda de la informacion.
solo me reconoce string y me da un mensaje de erro que indica q se espera un string, gracias

dwBuffer le_buffertype
Int li_buffers, li_items, li_index
Long ll_row_counter, ll_rows_buffer
String ls_column_name,ls_col_type,ls_insert_item
String ls_buffertype
integer ls_insert_number

ls_column_name = ddlb_filtercol.text

ddlb_data.Reset()

ls_col_type = dw_1.Describe(ls_column_name+".ColType")

ls_column_name+""+ string(le_buffertype))
//Aqui se carga los datos dentro del objeto ddlb.data del datawindow seleccionado
le_buffertype = Primary!
ll_rows_buffer = dw_1.RowCount()
For li_buffers = 1 to 2
For ll_row_counter = 1 to ll_rows_buffer
If left(ls_col_type,4) = "char" then
ls_insert_item = Trim(dw_1.GetItemString(ll_row_counter, ls_column_name, le_buffertype, true))
ElseIf left(ls_col_type,7) = "decimal" then
ls_insert_item =string(dw_1.GetItemDecimal(ll_row_counter, ls_column_name, le_buffertype, true))
ElseIf left(ls_col_type,8) = "datetime" then
ls_insert_item =string(dw_1.GetItemDatetime(ll_row_counter, ls_column_name, le_buffertype, False))
ElseIf left(ls_col_type,4) = "long" then
ls_insert_item =string(dw_1.GetItemNumber(ll_row_counter, ls_column_name, le_buffertype, False))

//inserto el item
ddlb_data.InsertItem(ls_insert_item,1)

Next
le_buffertype=Filter!
ll_rows_buffer=dw_1.FilteredCount()
Next