Get a reminder if a field of a lead remained unchanged for X days

[Plouff]

Hello,

I'd like YetiForce to help me handle the followup with my current leads.

Let's say I have a custom field for leads: step1, step2, step3, step4.
I'd like to get a reminder (or email or something else) to do come back to a lead if it stayed in any step for more than 2 days, and if the lead status is "in realization".

I tried using a workflow for this but I couldn't find a solution.
There is the "modified time" condition, but not regarding a specific field:

It is possible to do that with YetiForce?

Thank you :)!