It may already be too late, but for our system we took a different approach for translations. All of our forms and captions, and also any messages displayed by the system, are defined as translatable strings. Then, for any translation service we just need to send them the extract of the translatable strings in a plain text file for them to translate using the text editor of their choice. eg: Notepad.
Once they've finished the translation we simply load in the updated translatable strings from the plain text file. This avoids having to send the translation service anything other than plain text files and vice versa.
Actually, we took this a step further and allow administration users to translate the strings on the fly. This has the added advantage of allowing some sites that are still English speaking to translate their strings as well to reflect their terminology. eg: Zip Code versus Postal Code, County versus State, etc.
There will be a one-off hit to convert all your string literal captions and error messages into translatable strings, but I thought it worth mentioning in case that is a better long term option for you.
Cheers,
BeeJay.