Looking to convert Oracle "DEFINE" statement to a Teradata solution.

Database

Looking to convert Oracle "DEFINE" statement to a Teradata solution.

I'm new to Teradata and I'm finding my way around.  I am in the process of converting our ORACLE scripts to TERADATA.  I need help trying to come up with a solution for the following task.

In ORCALE, I'm doing the following.

DEFINE  varstring1 = "ABC123";

DEFINE  varstring2 = "456DEF";

DEFINE  varstring3 = "YYYY";

DEFINE  varstring4 = "XXXX";

DEFINE varstring5 = "&varstring3,&varstring4";

select &varstring1,  &varstring2,  &varstring5

from source_tab a;

Is there a way in Teradata to achieve the same with or without BTEQ?  Is it creating a macro? Declare SET? other?

Need help!  Thanks!