How to bring the control back to custom program after calling a std trans?

Hi experts,

There is an issue which i am facing, i am calling a standard transaction from my Z program, once i am into the transaction, i enter some data and save it...now after saving the data if the user press back on the std transaction screen the control should return to my Z program...can it be done?? if yes how.... i tried searching for user as well as screen exits but there aren't any....please help