Were you looking to create a new tab next to Details in defects module and place some of the fields there??If so you can try below sample in your workflow .For more information as mentioned by Trudy earlier ,you can refer to the admin guide-->workflow section-->Workflow examples -->Customizing defects module dialog box and refer to setfield app section.
'Details Tab
SetFieldApp "BG_USER_18", True, False, 0, 39
SetFieldApp "BG_USER_09", True, False, 0, 40
' First Tab
SetFieldApp "BG_USER_10", True, False, 1, 0 1 represents Page Num(tab1) and 0 represents View Number
SetFieldApp "BG_USER_11", True ,False, 1, 1
'Second Tab
SetField App "BG_USER_12", True,False, 2,0
SetFieldApp "BG_USER_13", True, False , 2,1
