I guess you want to modify a variable value to pause execution of some step. If so, it is not possible as started build will get a snapshot of variables, and the build will not see subsequent modifications not made in same build.

It should be that for variables set like promptSetting, certain steps can be skipped before the actual run. The skip page could be placed under the Specify Build Options page that appears after clicking the Run button, but it should only allow skip operations for the step page.

You may achieve this via variables, for instance, check if variable value equal to certain value in your step execute condition. This way, you can select to skip desired steps by setting variable to certain value in the variable prompt page.