Alternate between 2 staves and 1 stave in orchestral instruments
I'm writing an orchestral score with 4 French Horns. In general they are organized in 2 staves, 1-3 and 2-4, but sometimes I need 1 and 3 or 2 and 4 on separate staves. To accomplish this I use 2 staves, one for 1-3 to be used most of the time and one for 3 when the both instruments require different staves. So by hiding empty staves the F.Hrn 3 only appears for systems containing separate parts. However, when not empty, the first staff continues being labelled F.Hrn 1-3.
Is there a neat way to make the label alternate between F.Hrn 1-3 when both instruments are on the same staff and F.Hrn 1 when they are separate?