How to call conversion_exit_xxxx_input FM dynamically

Hi ,

I want to call FM conversion_exit_xxxx_input dynamically.

xxxx will be different for different data elements.

eg : xxxx is ALPHA for LIFNR and CUNIT for KMEIN

if the data element has conversion exit , i would like to call tht FM.

Any pointers , please help.

Regards ,

Laxmi.