Whenever you want to identify dynamic objects, use "Index" 
(e.g. #1), "Window Location" or "Prior text". You can use 
them together using "multitag" .Generally, those properties 
dont change in dynamic objects

You can use regular expression supported in 4test
for example for a window whose tag is 
"$WelcomeXYZ"

You can make it dynamic using regular expression
by replacing the tag by
"$Welcome???" or "$Welcome*"

You can use regular expression supported in 4test
for example for a window whose tag is 
"$WelcomeXYZ"

where XYZ keeps changing depending on user login or say 
environment due to which scripts fail.
You can make it dynamic using regular expression
by replacing the tag by
"$Welcome???" or "$Welcome*"