Airport Express as access point non-Apple router's network?

[hatrabbit]

I have a first generation Airport Express and I'd like to use it as an access point on a friend's network with another brand's router. Here's what I have in mind, hopefully others here can confirm/deny that this will work:
In the Internet tab of the Airport Express I will choose manual IP addressing and pick an address on the same subnet as the main router that's outside the range the router distributes.
In the Wireless tab I will choose Create a Wireless Network, name it identically to the existing network with identical security, and choose a non-overlapping channel.
The Airport Express will be connected by ethernet cable to a Lan port of the main router.

This should work, right? Thanks.

 

[Altemose]

In the Internet tab of the Airport Express I will choose manual IP addressing and pick an address on the same subnet as the main router that's outside the range the router distributes.
In the Wireless tab I will choose Create a Wireless Network, name it identically to the existing network with identical security, and choose a non-overlapping channel.
The Airport Express will be connected by ethernet cable to a Lan port of the main router.

This should work, right? Thanks.

Yes. Ensure that the IP is within the range of the other router. Another option is to connect it via DHCP and use a DHCP reservation on the other router.