Sure. You can just do a string concat() of the URL parameters based on some data source:
%%[
var @rows, @row, @rowCount, @numRows, @zip, @i, @url
set @zip = "55555"
set @numRows = 0 /* 0 means all */
set @rows = LookupOrderedRows("PatientInfo",@numRows,"patientID desc, patientAction asc","patientZip", @zip)
set @rowCount = rowcount(@rows)
if @rowCount > 0 then
set @url = "http://externalurl.com"
for @i = 1 to @rowCount do
var @patientID, @patientAction
set @row = row(@rows,@i)
set @patientID = field(@row,"patientID")
set @patientAction = field(@row,"patientAction")
set @url = iif(@i==1,concat(@url,"?"),concat(@url,"&"))
set @url = concat(@url,"patient",@i,"ID=", @patientID)
set @url = concat(@url,"&patient",@i,"Action=", @patientAction)
next @i
else
outputLine(concat("No patients found"))
endif
]%%
<a href="%%=redirectto(@url)=%%">external URL</a>