1) Welcome to the Party!
2) As you are obviously new here, I have some suggestions to help us all help you:
When you post, please post your entire configuration including (but not limited to) your installation method (11.X.X?) and vicidial version with build (VERSION: 2.X-XXXx ... BUILD: #####-####).
This IS a requirement for posting along with reading the stickies (at the top of each forum) and the manager's manual (available on EFLO.net, both free and paid versions)
You should also post: Asterisk version, telephony hardware (model number is helpful here), cluster information if you have one, and whether any other software is installed in the box. If your installation method is "manual/from scratch" you must post your operating system with version (and the .iso version from which you installed your original operating system) plus a link to the installation instructions you used. If your installation is "Hosted" list the site name of the host.
If this is a "Cloud" or "Virtual" server, please note the technology involved along with the version of that techology (EG: vSphere Version 6.X.X). If it is not, merely stating the Motherboard model # and CPU would be helpful.
Similar to This:
Vicibox 11.X.X from .iso | Vicidial X.X.X-XXX Build XXXXXX-XXXX | Asterisk X.X.X | Single Server | No Digium/Sangoma Hardware | No Extra Software After Installation | Intel DG35EC Mbd | Core2Quad Q6600 CPUs
3) There are AGI scripts in /var/lib/asterisk/agi-bin/ which provide examples for every function Vicidial has. Modifying one to "press 1" and then provide some dtmf tones would merely require an understanding of the perl language well enough to steal snippets from existing scripts. Note that while these are Vicidial scripts, they are written to run as Asterisk interface scripts: AGI is its own language and can be accomplished in PHP or PERL. These examples are (AFAIK) all in PERL, but what you describe is something that could be written in either language equally well ... but in PHP you would not have examples in front of you.
4) You left off some details: Is it always "press 1, then play some DTMF tones" or is it sometimes a different button press to initiate? Where do you get the DTMF tones? Do you make them up or do you have to read them from a screen ... or something else?
Happy Hunting!