Setting SET/GET Parameters in the Test Script 
You can set SET/GET parameters of the application to be tested in the test script. The SET/GET parameters are set in the session of the current target system of the test script. Insert the following in the script text:
%[Parametername] = <Wert>.
This also works when using SAPGUI commands. You have to set the parameter before the start of the controlled SAPGUI.
Syntax
... … %EC_SEL_OBJ_TYPE = 'RB_ECATT_SCRIPT'. %D_ECSC_NAME = 'SOME_TESTSCRIPT'. SAPGUI ( SECATT_01 ). …
If SECATT_01 contains the recording of transaction SECATT, this script starts the transaction SECATT; the Test Script radio button is already selected and the name of the test script is displayed in the corresponding field.