I just want to confirm: You are ignoring or diverting to voicemail on your cell phone, not the IP phone, correct?
Assuming that's accurate: No there is not. We have no indication what the cellular handset/carrier has done with the call. The only thing CUCM can base its decision on is whether the call was answered within the answer-too-soon/answer-too-late window. If the call was answered outside of that window (which includes being answered by the cellular voicemail), CUCM rules out the remote destination and will follow the call forwarding rules of the DN.