Escape input mask value

I want my input mask to be "+971#######". I can replace the # with 9, but the first 9 is literal. I want it to be a mandatory 9 in my mask, how can I do that? Thanks!

Unfortunately, that's not possible using the input mask. That would have to be done using the gform_validation hook and custom validation. The input mask forces a format, but won't validate the value itself for something that granular. So you would just setup the input mask how you want it displayed and then use the hook to make sure it starts out with the 9.

http://www.gravityhelp.com/documentation/page/Gform_validation contains an example of usage as well as a link to a more thorough example.