One solution is to use a LABEL with the presentation style textFormat set to HTML. Then it is a case of displaying to this the same HTML you would use in a webpage to trigger the launch of the mail tool, or a phone call.
In your form ...
LABEL f01 = formonly.email_address, STYLE="html";
LABEL f02 = formonly.phone_number, STYLE="html";
In your stylesheet ...
<Style name="Label.html">
<StlyeAttribute name="textFormat" value="html" />
</Style>
In your 4gl ...
DISPLAY '<a href="mailto:name@example.com">Mail Name</a>' TO email_address
DISPLAY '<a href="tel:99999999">Phone Name</a>" TO phone_number
Hope that helps,
Reuben