Presuming you mean α? Easiest thing is either the Character Map or google it and copy+paste (which is what I did). There is probably some combo of alt+number pad that would give it, but I dont' know it and haven't been able to find it as of yet on google
Chikis also asked how to write out the alpha symbol in tex, I am not sure if this is a different question or the same question.
Based on skimming your other thread, I think you mean this: LaTeX code: [noparse]\(X \propto m^2 n^3\)[/noparse] Rendered output: \(X \propto m^2 n^3\)
