Concatenate variables storing table/field names

Hi All ,

I want to concatenate the values stored in fields of structure EQUI . I am reading these fields from a z table . For example :

My Z table has 2 columns  -  ZTAB & ZFIELD with following 2 records :

                                              EQUI   ERNAM

                                              EQUI   AEDAT

At run time , I have access to EQUI structure .On reading the above ztable I got 2 lines in my internal table it_ztable .

Now what I want  system should read values of above fields from EQUI structure and  concatenate values of  EQUI-ERNAM and EQUI-AEDAT .

In other words it should work like following statement :

CONCATENATE EQUI-ERNAM  EQUI-AEDAT into var_string.

Here if at runtime ERNAM and AEDAT has value : rsudesh 20150810 then var_string should have value " rsudesh20150810"

Here in my z table there can be any field from EQUI table . How to write the code . I don't want to use if and else to compare each field . I have tried using field symbols but its not working .

With Regards