Calling a method with a char parameter

Hello,

how to call a method in script with a char parameter with TestComplete 10.60.3387.7 ?

The application was developed on QT (version 5.4.0), the object "Sys.Process("se_plage").QtObject("MainWindow").QtObject("centralWidget").QtObject("tabWidget").QtObject("qt_tabwidget_stackedwidget").QtObject("PlagesHoraires").QtObject("graphicsViewPH")" provides access to a method "ProgHebdoBAToListCCO_" as with description "Sub ProgHebdoBAToListCCO_(Param1 as char)".

I tried the following code :

param1 = "02:00"
Sys.Process("se_plage").QtObject("MainWindow").QtObject("centralWidget").QtObject("tabWidget").QtObject("qt_tabwidget_stackedwidget").QtObject("PlagesHoraires").QtObject("graphicsViewPH").ProgHebdoBAToListCCO_(param1)

I get an error (view attachments).

Thank you in advance