0v-5v (aka expression) control: algorithm control ideas

[Pete Moore]

Now I'm using a pot to control analog delay speed.
A precise, "slight"increase of speed creates the wondrous sounds Steve Steven's (Eyes without a face etc.) Got as the bucket brigade catches up to the new control voltage setting.
0v-5v appears across a linear pot (plugged into expression jack), the wiper presents the variable voltage to the ring...speed control.
I want a .2v sweep (est.) @about 4v-6v (pot positions) to occur like when I "bump the speed control (slightly up). If lucky, a cascade of frequency swept delay returns slowly return to input frequency as the bucket brigade :recovers from the speed setting decrease.
I want to do it say...
With resistor ladder feeding v-control voltage sweep, to a slow-fill capacitor, making voltage slow sweep from ~4.2 to 4.4v at first ladder step, 4.4v to 4.6v second step, each step a half second sweep of +.2volts.
Estimated...
And wondering if theres another control voltage control method that would reliably get the sweeping frequency delay of bucket brigades recovering to slight increase of speed setting.