Have you looked at "Implementing a Combo Editor" here:
Yes the thing here is its multiple parameter with predefined selection, so i guess it should be a parameter.
OnFormShow, use this event handler. When the form shows, populate the drop down values in the combo box. Then, when OK is clicked on the form, take the value from the combo box as selected, and pass it through as the value for the parameter.
Look at this Log Message key word test parameters:
it has multiple parameters with different type editor, more or lesss this is what i need. I can only setup a text box type , what i need is a multiple parameter editor with predefined combo selection. Is this possible in extension?
Check out this article. https://support.smartbear.com/testcomplete/docs/working-with/extending/script/creating/keyword-test-operations/basic.html
Specifically... scroll down until you get to
(Optional) Creating the operation’s edit form
Besides in-place editing in the Keyword Test editor, custom operations can use forms to provide visual access to their parameters. This edit form is displayed when the user adds the operation to the test or double-clicks an existing operation in the test. See Creating the Operation Setup Routine and Using Forms in Script Extensions.
Basically, you would replace the default form with your own custom form.
Also, see
