Can I say "estar en una carta"?

Can I say "estar en una carta"?
 

"En la carta de Héctor van a estar unos datos importantes."

Is the use of "estar" correct in this sentence?



Gracias por adelanto.

"Gracias por adelantado". :)

The use of "estar" is correct. That's where the data will be.

·Voy a estar en el restaurante.
·Estaremos en casa.


Edit: Your thread title has been corrected from "Can I say "estar en la un carta"?" to "Can I say estar en una carta?"
Either "la" or "una". Never "en la una carta".... and "carta" is a feminine. :)

Thank you for correcting my other mistake too! :3 :)

The 'la un' was a typo.