Automatic Text Size

I'm sorry if this topic has been covered before, but I can't see it in the search.
What I wnat is a menu item that will select a text style say "iso" select a finished size say"2.5mm" and then the scale that the draeings is to be plotted at say"1:100"
Then when I use Mtext or Dtext the font size is correct to give me 2.5mm text at 1:100 ie 250mm text.
One other problem, the office uses a mix of Autocad versions from 2000LT to 2005Autocad. that means autolisp will not work.
I can solve the problem by craeting text styles for each size and scale, but thet is not an elegant way. I'm sure that using dimscale would be the solution but how?
Dellboy

 

What I wnat is a menu item that will select a text style say "iso" select
a finished size say"2.5mm" and then the scale that the draeings is to be
plotted at say"1:100"

text at 1:100 ie 250mm text.

Dimscale * intended plotting size = text height

Ex. 100 * 2.5 = 250

You could do the calculation in a diesel expression in a menu macro. You
shouldn't have to choose the dimscale as this can be retrieved from the
drawing.