If you're not a type designer without the necessary tools, then Illustrator might be your option.

Otherwise, depending on your adherence to the EULA of the font and the availability of the proper font tools, you could cannibalize the ½ symbol and hack it in.

Or, depending on the circumstances, you can use one from a different font. (Although, it's not going to be easy to match Eurostyle.)

You can build it in your layout application, by setting the superior "one", followed by "fraction" and superior "three", with appropriate baseline shift and kerning.

I don't know if that process would produce a match for the other fractions in that particular font.

Thank you for your reply Dan, I can in fact do the hack... but ugh -.- too many pages to finish and so little time! and well the font is part of Adobe's font folio 11 so yeah once again ugh... EULA!
Of we go with illustrator, Cheers!
Any other suggestion is welcome!

Oooops, was typing so I just saw ur answer Nick. Again Thank you!
There was a annoying difference with the fraction /
however the 1 and 3 worked great... :)
BOOOooo!
Once again I appreciate your help!

Adobe's EULA is actually quite generous, and it's my non-lawyer's opinion that this is the exact kind of modification it allows, as long as you don't re-distribute.

There was a annoying difference with the fraction /

The fraction character (a.k.a. "virgule") is different from the slash, and should be the same in the font when both an isolated character, or when part of a composite fraction.

Dan Rodney has an InDesign script for proper fractions. I haven't tried it so cannot comment on this one, but am pretty happy with his Make Book Jacket script.

The fraction character (a.k.a. “virgule”)

Shift-option-1 on the Macintosh keyboard.

@Nick Shinn & kentlew
the “virgule” in Eurostile LT Std is unfortunately the same as slash.
@k.l.
I haven't tested the Pro features however there is in fact a difference between the native otf fractions available and the ones "styled" by the script. So I don't know... has anyone tested the Pro version here? Any feedback? Would be informative!

Thanks for all the help folks!

I think you better go with the Eurostile Next package, it seems to have self building fractions:

http://www.linotype.com/270804/eurostilenextproregular-charactermap.html