Title Box Rotation

Is there a way to rotate a title box control within a panel?

No. The best Igor can do is either a drawing text item, or put a graph subwindow in the panel with a rotated annotation:

Window Panel0() : Panel
    PauseUpdate; Silent 1       // building window...
    NewPanel /W=(150,77,450,277)
    Display/W=(90,36,137,86)/HOST=#
    TextBox/C/N=text0/O=90/A=MC "Text"
    RenameWindow #,G0
    SetActiveSubwindow ##
EndMacro

I think a DrawText command will be simpler:

Window Panel0() : Panel
    PauseUpdate; Silent 1       // building window...
    NewPanel /W=(150,77,450,277)
    SetDrawLayer UserBack
    SetDrawEnv textrot= 90
    DrawText 51,45,"Text"
EndMacro