Hot to use a variable in WinFormsObject() in VBScript?

I want to pass a parameter to below line for "txtPatterName" but TC complete fails to evaluate.

myparam = "txtPatterName"

Set Obj = Sys.Process("GemCat_Gui").WinFormsObject("frmPatternMetaData").WinFormsObject("grpPatternID").WinFormsObject("txtPatterName")

I am aiming to something like (not sure if concatenation if right):

Set Obj = Sys.Process("GemCat_Gui").WinFormsObject("frmPatternMetaData").WinFormsObject("grpPatternID").WinFormsObject(" & myparam & ")