Looking for Triggering condition in ECC

Hi,

I need some help here please.

My issue: I am having e user exit that i wrote will populate a custom field (say X) of mine when the order saves in R3.This works fine when i am saving the order. But when the ORDER replicates from CRM with the value in this custom field X i do not want my user exit in R3 to execute.

What is happening is the user exit in R3 is executing and the value of the custom field is getting overwritten.

Is there any way we can say the user exit to trigger/execute only if the ORDER is created in R3 and if the order comes from CRM it should not.

Any suggestions/workaround are much appreciated.

Thanks,

Karuna.