constructing variables

[Dr. med. Kai Lautenschläger]

\version "2.19.7"

Hi everyone!

is it possible to construct variables from others? I want to construct 

\tempo "Text" 4=80

from the variables

tempoText = "Text" and
tempoNumber = "4=80"

that are defined at two different places in a complicated file structure 
(\include)

I tried:

\version "2.19.7"
tempoText = "Text" and
tempoNumber = "4=80"
{
        \tempo \tempoText \tempoNumber
        a4 
}

with an without quotation marks, but nothing worked. I suppose I just can’t see 
the obvious and just looked for the wrong keywords in the documentation. Can 
anyone point me in the right direction.

Thanks

Kai