You can do something like this with regular expressions. But the case abap_true and the repetition of the variable cond_recort feels a bit ugly
CASE abap_true.
WHEN cl_abap_matcher=>matches( pattern ='ST'
text = cond_record ).
WHEN cl_abap_matcher=>matches( pattern ='VAT'
text = cond_record ).
WHEN cl_abap_matcher=>matches( pattern ='CST.+'
text = cond_record ). WHENOTHERS.
ENDCASE.
Christian