To enter the program name in a variable, precede the variable name with the character &.
Example
Define the variable W_CALL
W_CALL = 'INQCL01'
CALL &W_CALL W_PARA01 W_PARA02
W_CALL = 'UPDCL01'
CALL &W_CALL W_PARA01 W_PARA02 W_PARA03
Therefore you can call programs having different names as well as different parameters with the same variable.
Warning: No interactive control is performed. Errors are only detected during the program execution.