Is there a way to get the index of a key in Request.Form?

Request.Form has the following keys...
OptionsList = Index 0
OptionsSelected = Index 1
CovCdCMP = Index 2
CovCdCOL = Index 3
CovCdPIP = Index 4
PIP*Attribute*5 = Index 5
PIP*Attribute*9 = Index 6
CovCdLBD = Index 7
LBD*Attribute*2 = Index 8

So, I know I want to start at Request.Form("CovCdPIP") which is Index 4 in my example, but I don't know that it's Index 4 yet at the point I'm at in my code. All I know is I need to start looping through Request.Form at CovCdPIP, and stop after PIP*Attribute*9

If I could get the index of CovCdPIP, then I could just do something like...
For LCV = StartIndex to EndIndex
Do some code

instead of...
For LCV = 0 to Request.Form.Keys.Count - 1
Do some code

Any suggestions?