difference between line command in .do and display in modelsim

Hi,

in my file .do to create and launch simulation when i modify my signal with command line "wave modify -driver freeze -pattern clock -initialvalue 0 -period 25ns -dutycycle 50 -starttime 0ns -endtime 1000ns NewSig:/sigmed_top/clk_ext"

there is factor 100 and i get a signal with period of 250ps and endtime 10ns

If i "modify" signal without changing parameters and valid, it's ok but i don't find a command line to resolve my probleme. I think the problem comes in Simulate/runtime option ( parameter: "default run")

thank you for your answers

PS: i use modelsim starter edition 10.1b