This is a sample macro on how to set the http proxies in iMacros for Firefox (Proxies are called from a proxy list file named proxylist.csv)

VERSION BUILD=6240709 RECORDER=FX
TAB T=1
SET !ERRORIGNORE YES
SET !DATASOURCE proxylist.csv
SET !DATASOURCE_COLUMNS 2
'Increase the current position in the file with each loop
SET !DATASOURCE_LINE {{!LOOP}
'clear cookies and cache:
CLEAR
URL GOTO=about:config
'some proxies are slow, set the timeout to 90 seconds:
URL GOTO=javascript:gPrefBranch.setIntPref("network.http.keep-alive.timeout",900);
URL GOTO=about:config
'set the proxy URL
URL GOTO=javascript:varprefb=Components.classes["@mozilla.org/preferences-service;1"].getService(Components.interfaces.nsIPrefBranch);varstr=Components.classes["@mozilla.org/supports-string;1"].createInstance(Components.interfaces.nsISupportsString);str.data="{{!COL1}}";prefb.setComplexValue("network.proxy.http",Components.interfaces.nsISupportsString,str);
URL GOTO=about:config
'set the proxy port:
URL GOTO=javascript:gPrefBranch.setIntPref("network.proxy.http_port",{{!COL2}});
URL GOTO=about:config
'turn the proxy on
URL GOTO=javascript:gPrefBranch.setIntPref("network.proxy.type",1)
[/code]
This is a sample macro on how to set the socks proxies in iMacros for Firefox (Proxies are called from a proxy list file named proxylist-socks.csv)
[code title="iMacros script"]
VERSION BUILD=6240709 RECORDER=FX
TAB T=1
SET !ERRORIGNORE YES
SET !DATASOURCE proxylist-socks.csv
SET !DATASOURCE_COLUMNS 2
'Increase the current position in the file with each loop
SET !DATASOURCE_LINE {{!LOOP}
'clear cookies and cache:
CLEAR
URL GOTO=about:config
'some proxies are slow, set the timeout to 90 seconds:
URL GOTO=javascript:gPrefBranch.setIntPref("network.http.keep-alive.timeout",900);
URL GOTO=about:config
'set the proxy URL
URL GOTO=javascript:varprefb=Components.classes["@mozilla.org/preferences-service;1"].getService(Components.interfaces.nsIPrefBranch);varstr=Components.classes["@mozilla.org/supports-string;1"].createInstance(Components.interfaces.nsISupportsString);str.data="{{!COL1}}";prefb.setComplexValue("network.proxy.socks",Components.interfaces.nsISupportsString,str);
URL GOTO=about:config
'set the proxy port:
URL GOTO=javascript:gPrefBranch.setIntPref("network.proxy.socks_port",{{!COL2}});
URL GOTO=about:config
'turn the proxy on
URL GOTO=javascript:gPrefBranch.setIntPref("network.proxy.type",1)

Enjoy